United States
Environmental Protection
Agency
A Lexicon of Cave and Karst
Terminology with Special
Reference to Environmental
Karst Hydrology

(Supercedes EPA/600/R-99/006, 1/'99)

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                                                                  EPA/600/R-02/003
                                                                    February 2002
A LEXICON OF CAVE AND KARST TERMINOLOGY


              WITH SPECIAL REFERENCE


    TO ENVIRONMENTAL KARST HYDROLOGY
               (Supercedes EPA/600/R-99/006, l/'99)
  National Center for Environmental Assessment-Washington Office

                Office of Research and Development

               U.S. Environmental Protection Agency
                      Washington, DC  20460
                                                         Recycled/Recyclable
                                                         Printed with vegetable-based ink on
                                                         paper that contains a minimum of
                                                         50% post-consumer fiber content
                                                         processed chlorine free.

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                                     DISCLAIMER

This document has been reviewed in accordance with U.S. Environmental Protection Agency policy
and approved for publication.  Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
                                           n

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                                CONTENTS
PREFACE TO THE SECOND EDITION	iy

PREFACE TO THE FIRST EDITION	y

AUTHOR AND REVIEWERS	yi

INTRODUCTION	1
GLOSSARY
      A...
      B ...
      C	
      D	
      E	
      F	
      G	
      H	
      I 	
      J 	
      K	
      L	
      M ....
      N	
      O	
      P	
      Q	
      R	
      S	
      T	
      U	
      V	
      w	
      Y	
      Z	

REFERENCES
...3
...4
..15
..26
..54
..67
..73
..81
..90
..98
.105
.106
. 112
. 118
. 127
. 131
. 134
, 151
, 152
, 162
, 190
 200
 203
 206
 211
 212
 213
                                    111

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                           PREFACE TO THE SECOND EDITION

       Release of the first edition of this lexicon was well received and resulted in two printings. The
first edition is again in short supply, but rather than going through a third printing, an updated edition
was deemed appropriate. Since the release of the first edition, additional definitions related to
biospeleology, courtesy of Dr. William R. Elliott of the Natural History Division of the Missouri
Department of Conservation, have been added. Additional definitions obtained from the Australian
Speleological Federation also have been added.
       Researchers and the general public alike will find these additions useful as they work their way
through the published literature.  For this second edition, the literature search is current to 2002. To be
sure, this updated lexicon is far from complete and will more than likely be updated in a few years.
                                              IV

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                           PREFACE TO THE FIRST EDITION

       The National Center for Environmental Assessment-Washington Office (NCEA-W) has
prepared this document for the benefit of the regional offices and public in general due to the need to
understand the terminology common to the field of karst.  It is a glossary of most terms that have
some relationship to the field of environmental karst as well as specific karst terms.  It includes many
foreign terms because much of the karst research is conducted in foreign countries and published
using local terminology.  In many instances, common environmental terms are defined in such a way
as to specifically reference karstic phenomena.
       The purpose of this document is to serve as a technical guide to regional  offices and the public
in general who must read the karst literature or who must hold discussions with karst researchers. It is
intended that this document remove much of the confusion surrounding many of the karst terms.
       The literature search supporting this lexicon is current to 1998.
                                              v

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                              AUTHOR AND REVIEWERS


      The National Center for Environmental Assessment-Washington Office within the Office of

Research and Development was responsible for the preparation of this document and provided overall

direction and coordination during the production effort.


AUTHOR/COMPILER

      Malcolm S. Field, Ph.D.
      U.S. Environmental Protection Agency
      National Center for Environmental Assessment-Washington Office
      Washington, DC


REVIEWERS

      Stephen R. Kraemer, Ph.D.
      U.S. Environmental Protection Agency
      National Exposure Research Laboratory
      Ecosystems Research Division                                           :
      Athens, GA

      Arthur N. Palmer, Ph.D.
      Department of Earth Sciences
      State University of New York
      Oneonta, NY
                                            VI

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                                     INTRODUCTION
       Several attempts to classify karst terminology in an organized manner have been attempted in
the past.  The last few glossaries of karst terminology were organized in the late 1960s and published
in the early 1970s.  Since that time, many new terms related to karst in general have come into use
throughout the world while other older karst terms are seldom used nowadays. In the mid 1990s the
British Cave Research Association (BCRA) published and updated a dictionary that covers the general
area of karst and caves, but did not focus on environmental issues.
       Many of the more recent karst terms are related to the upsurge in environmentalism and the
recognition among karst cognoscenti that karst terranes are much more sensitive to man-induced
effects on the environment than are other types of landscapes. In an attempt to be as broad as possible
in this glossary, terms related to general hydrology and hydrogeology, common karst rock and mineral
types, and many of the descriptive terms used in speleology even where they relate to specific
localities, have been included.  No attempt was made to exclude foreign karst terms although many
are no doubt, missing. This has led to a much larger manuscript than was originally intended when
this project was initiated, but it has provided for a more comprehensive document.
       Because many non-karst professionals, whether working on basic research or on
environmental problems, need to have a general working knowledge of karst terminology, this
glossary was developed to provide an up-to-date reference for more modern definitions of karst terms
both currently in usage and now defunct. As with any undertaking of this sort, numerous omissions
will be shown to be evident,  hi other instances, disagreements regarding definitions will arise, hi the
event that readers of this glossary find various omissions or incorrect definitions, it would be greatly
appreciated if the necessary corrections be forwarded to the author so that the glossary may be updated
in the future.
       As a final note, it should be pointed out that a list of references  for the definitions are included
at the back of this glossary and citations are provided when appropriate. In many instances,
duplication of definitions from previous glossaries were employed to avoid changing the original
definitions.  However, efforts were not always attempted to cite the exact source for each definition as
this would have greatly lengthened this already excessively long manuscript; secondary citations have

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been provided.  Exact citations would also have resulted in confusion where several definitions were
utilized in the writing of a single clear definition for any particular term. In no instance was it
intended that the work of others be appropriated, only that this glossary be as comprehensive and clear
as possible while avoiding excessive clutter. Also, where definitions were deemed to be incorrect or
poorly worded, alternatives have been written.

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GLOSSARY OF TERMS

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                                                accidental An animal accidentally living in
abime.  (French.)  1. An abyss. 2. A wide,
   deep shaft, in limestone, the walls of which
   are vertical or overhanging[101.

ablation.  The  wearing away of ice or snow
   through the process of evaporation1'63.

abney level.  Type of clinometer with a
   bubble tube used in cave survey to
   determine vertical angles[25].

abris sous roche.  (French.) See rock
   shelter.

abseil. 1. (n.) A controlled descent of a
   rope using friction obtained by either
   wrapping the rope around the body in a
   particular way or passing the rope through
   a carabiner or passing the rope through a
   descender[25]. 2.  (v.) To do an abseil[25].
   Synonym: rappel.

absorption. The process by which
   substances in gaseous, liquid or solid
   form dissolve or mix with other
   substances1221.

abyss. Extremely great depthtI6].

accelerated corrosion. A localized
   concentration of solution intensity,
   produced by factors  favoring greater
   aggressivity  of the water in certain parts
   of the karstland creating differential
   solution rates and thereby a marked
   unevenness in the overall erosion of the
   karstland[19].  See also corrosion; alluvial
   corrosion.

accessory mineral.  Mineral constituents of
   a rock occurring in very small amounts[I6].
  a cave[25].

acclivity.  Ascending a slope[I6].

accretion.  Land addition by sediment
  deposition of a stream[I6].

accumulation. Building of new land by
  addition of sedimentary deposits1161.

acetylene.  An inflammable hydrocarbon
  gas, C2H2, produced by water reacting
  with calcium carbide. When burned,
  yields carbon dioxide as well as light[25].

acid.  Any chemical compound containing
  hydrogen capable of being replaced by
  positive elements or radicals to form salts.
  In terms of dissociation theory, it is a
  compound which, on dissociation in
  solution, yields excess hydrogen ions.
  Acids lower thepH. Examples of acids
  or acidic substances are hydrochloric acid,
  tannic acid, and sodium acid
  pyrophosphate[6].

acidity: The property of water having a pH
  below 4.5 that is caused by the presence
  of mineral acids. Usually expressed in
  equivalent amounts of calcium
  carbonate^161. See also alkalinity; pH..

acid mine drainage. Acid waters
  originating from surface or underground
  mine workings1161.

acoustic log. Geophysical borehole log
  measuring the speed of sound in rocks to
  determine porosity1161.

acoustic resistance.  The product of wave
  velocity and rock density indicating the

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  reflective power of a boundary between
  two strata1161.

activated charcoal, activated carbon.  A
  granular material usually produced by the
  roasting of cellulose base substances,
  such as wood or coconut shells, in the
  absence of air.  It has an extremely porous
  structure and is used in water
  conditioning as an adsorbent for organic
  matter and certain dissolved gases[6].  It is
  especially useful for adsorbing tracer
  dyes.

active cave. 1.  Cave containing a running
  stream. 2. Cave in which speleothems are
  growing. (Less common and less
  desirable usage.) Compare live cave[IO].

active glacier.  Glacier in the  stage of
  actively enlarging and moving as a result
  of accumulation of precipitation that
  exceeds the rate of ablation.

active water. Water with corrosive
  properties[16].

adaptation. An inherited structural,
  functional, or behavioral characteristic
  that improves an organism's chances for
  survival in a particular habitat[23].  See
  also mutation.

adiabatic. The property of thermodynamic
  process with no heat exchange1161.

adjusted stream. Stream flowing parallel
  to the strike of underlying beds[16].

adsorption. Adherence of gas molecules,
  ions, or molecules in solution to the
  surface of solids1221.
adsorption isotherm. A graphical
  representation of the relationship between
  the bulk activity of adsorbate and the
  amount adsorbed at constant
  temperature1221.

advection. 1. The process whereby solutes
  are transported by the bulk mass of
  flowing fluid[61. 2. Phenomenon of cool
  air mass intruding and interrupting
  evaporation and causing condensation due
  to heat loss[16l  See also convective
  transport.

aeolianite. See eolian calcarenite.

aeration.  The process of bringing air into
  intimate contact with water, usually by
  bubbling air through the water to remove
  dissolved gases like carbon dioxide and
  hydrogen sulfide or to oxidize dissolved
  materials  like iron compounds161.

aeration, zone of. See zone of aeration.

aerial photograph. Photograph of the
  landscape taken from  an airplane.
  Synonym air photo. See also stereo aerial
  photographs.

aerobic. A property of aquatic life forms
  that can exist only in the presence of
  oxygen.  See also anaerobic.

age of caves. The ages of individual  caves
  may vary enormously. In most regions
  the youngest cave passages have reached
  their present dimensions during the last
  10,000 years, or since the last Pleistocene
  glacial retreat.  In higher latitudes most
  caves can be related to erosion during the
  later Pleistocene climatic variations of the
  last million years, and older caves have

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  largely been removed by continuing
  surface lowering. In tropical regions less
  interrupted erosion conditions have
  encouraged survival of older caves; the
  Mulu caves of Sarawak include large
  passages at least two million years old.
  Relict caves hundreds of millions of years
  old may survive in some buried
  limestones, but are commonly filled with
  younger sediments (see neptunian
  deposits), minerals or, very rarely,
  igneous rocks. These fill materials may
  themselves be dateable, either on the
  basis of contained fossil material
  (including pollen), by comparison with
  similar rock types that occur at the
  surface or by isotopic age determination
  methods identical to those applied to
  suitable surface rock materials.  See also
  dating of cave sediments191.

aggradation. Land addition through
  sediment deposition1161.

aggrading river. River that is actively
  elevating its bed by deposition of
  sediments1161.

aggregate. Grain mixture loosely held
  together1161.

aggregation. The formation of aggregates.
  In drilling fluids, aggregation results in
  the stacking of the clay platelets face to
  face; as a result, viscosity and gel strength
  decrease[6].

aggressive. Referring to water which is still
  capable of dissolving more  limestone,
  other karst rock, or speleothems[25].

aggressive water. 1. Water having the
  ability to dissolve rocks. In the context of
  limestone and dolomite, this term refers
  especially to water containing dissolved
  carbon dioxide to form carbonic acid or,
  rarely, other acids. 2. Quality of waters
  that attack metals and concrete chemically
  by dissolution1101.

aggressiveness.  A measure of the relative
  capacity of water to dissolve rock
  material. In the context of karstification
  and speleogenesis this usually concerns
  the dissolution of limestone or dolomite
  by the action of dissolved carbon dioxide
  (carbonic acid), though other acids may
  also be involved191.

aguada. (Spanish for watering place.) In
  Yucatan, shallow depression generally
  covering several hectares used for water
  supply1101.

A-horizon. The topmost eluviated horizon
  of a soil profile1161.

atle. See aisle.

air pocket, air bell.  1. An enclosed air
  space between the water surface and the
  .roofofacave[10]. 2. Part of a flooded
  passage where the ceiling rises above the
  water level  to create an air pocket isolated
  from the rest of the cave[9].

air separating tank. A tank in which
  desorbed gases are separated from a
  liquid and evacuated by pumping[16].

air-space ratio.  The ratio of (a) the volume
  of water that can be drained from a
  saturated soil or rock under the action of
   force of gravity to (b) the total volume of
  voids[22].

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aisle. An elongated high narrow traversable
  passage in a cave[IO]. See also crawl,
  crawlway; corridor; passage. Synonyms:
  (French.) aisle, aile; (German.) Kluft;
  (Greek.) farangothes ipoyios thiavasis;
  (Russian.) hod; (Spanish.) laminador
  vertical; (Turkish.) dor gecit;
  (Yugoslavian.) nisa.

albedo.  The ratio of reflected radiation to
  total radiation on a natural surface[16].

algal limestone. Type of limestone formed
  by calcium secreting algae[16].

alkali flat.  A salt covered or heavily saline
  depression in an arid environment1161.

alkaline. Any of various soluble mineral
   salts found in natural water and arid soils
  having a pB. greater than 7. hi water
   analysis, it represents the carbonates,
  bicarbonates, hydroxides, and
   occasionally the borates, silicates, and
   phosphates in the water[6].

alkalinity.  The property of water to
   neutralize acids. Usually expressed in
   terms of calcium carbonate equivalents116].
   See also acidity; pH.

allochthonous. Said of material originating
   from  a different locality than the one in
   which it has been deposited[16].  See also
   autochthonous.

allochthonous drainage.  Less common
   synonym for allogenic drainage[9].

allogeme stream.  A surface-water course
   flowing over a karst terrane, but fed by a
   spring (or springs) issuing from a non-
   karst terrane[20].  Synonyms: (French.)
  riviere allogene (cours d'eau); (German.)
  allochthoner Fluss (all. Wafierlauf);
  (Greek.) allothigenes ryax, orpotamos;
  (Italian.) corso d'acqua allogeno;
  (Spanish.) rio aloctono; (Turkish.) karst
  disi kokenli akarsu; (Yugoslavian.)
  alogena rijeka, alogena reka.

allogenic. Formed or generated elsewhere,
  usually at a distant place[1].  See also
  autogenic; recharge, allogenic; recharge,
  autogenic.

allogenic drainage.  Underground karst
  drainage that is derived entirely from
  surface run-off that originates on adjacent
  non-karstic, generally impermeable,
  rocks. Also allochthonous drainage. See
  also autogenic drainage191.

allogenic valley. A karst valley incised by a
  watercourse originating on impervious
  rock with a volume sufficient for it to
  traverse a limestone area on the surface.
  The valley is incised from the limestone
  contact and with the passage of time the
  river is increasingly likely to pass
  underground as the waters enlarge joints.
  Occasionally such a valley may represent
  the large-scale collapse of the cavern
  system along a subterranean stream or the
  enlarging of a series of karst windows1191.

alluvial. Pertaining to or composed of
   alluvium or deposited by a stream or
  running water161. Also applies to material
   lining the floor of a cave and deposits  at
   the mouth of a spring.

alluvial apron. A fan-like plain from the
   deposition of glacial outwash[16].

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alluvial channel. River or stream channel
  bed composed of unconsolidated alluvial
  material1161.

alluvial corrosion.  Greater intensity of
  solution, caused by the passage of water
  through unconsolidated deposits rich in
  carbon dioxide, thus increasing
  aggressivityt191. See also corrosion,
  accelerated corrosion.

alluvial fan.  A fan-like deposit of detrital
  material from steep mountain slopes[16].

alluvial plain. A plain formed by the
  deposition of water borne sediments1161.

alluvial veneer. A very thin cover of water
  borne sediments^161.

alluvium. A general term for clay, silt,
  sand, gravel, or similar unconsolidated
  material deposited during comparatively
  recent geologic time by a stream or other
  body of running water as a sorted or semi-
  sorted sediment in the bed of the stream
  or on its floodplain or  delta or as a cone
  or fan at the base of a mountain slope[6].

alpine karst. l.Karst formed at high
  latitude, or in polar regions regardless of
  altitude. 2. Almost synonymous with
  glaciokarst but restricted to areas of high
  altitude and relief*91. Synonyms:
  glaciokarst; nival karst.

alternative. Adjective used to designate an
  intake or resurgence operating only
  during rainy seasons; in some areas
  reversible; equivalent to intermittent.
  Also used as a noun[101.
alveolar.  1. Consisting of a honeycomb
  shape[16].  2. A specific erosional pattern
  resulting in a cellular structure^161. See
  also alveolization.

alveolization. (From the Latin word
  'alveolatus,' meaning hollowed out.)
  Pitting of a rock surface produced by
  wind loaded with sand, by water charged
  with carbonic acid, or by plant roots'101.
  See also alveolar.  Synonyms: (French.)
  alveolisation; (German.) Aeolisation ?
  Wabenverwitterung; (Greek.) kypselothis
  epiphania; (Italian.) alveolizzazione;
  (Spanish.) alveolizacion; (Turkish.)
  qukurla§ma\ (Yugoslavian.) alveolizacija.

ammeter. A meter used to measure the
  flow of water in a stream channel.
  Synonym: current metertl6J.

amorphous silica. Silica with no definite
  crystalline structure1161.

analysis, chemical. Laboratory procedure
  in water quality determination to identify
  chemical constituents'161.

analysis, complete chemical analysis.
  Chemical analysis of a water sample for
  physical, chemical, and bacteriological
  constituents1161.

analysis, core.  Petrophysical analysis of a
  rock core acquired through the process of
  boring a hole in rock with the intention of
  producing a core of rock as opposed to
  chips[I6].

analysis, morphometric. A geodetic and
  geometric description of basin, stream
  network, or sinkhole plain, the purpose of

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  which is to determine the frequency and
  hierarchy of occurrences116].

analysis, sieve. Mechanical grain size
  analysis by sieving an unconsolidated
  material through a series of sieves[16].

anastomosis. 1. The development of a
  network of branching, intersecting, and
  rejoining channels in a two dimensional
  system. Anastomosing tubes, or cave
  anastomoses, which are generally formed
  due to dissolution by slow, poorly
  directed, phreatic flow along a bedding-
  plane parting or fracture in limestone,
  represent an important element in the
  early stages of cave development.
  Individual anastomoses most commonly
  have a diameter of approximately 100
  mm and networks may contain hundreds
  of tubes. Most anastomoses are
  abandoned when one channel offers
  preferential flow conditions so that it
  increases in size at the expense of others.
  Such abandoned or relict anastomoses are
  commonly only exposed by subsequent
  wall or roof collapse1321. 2. A network of
  tubular passages or holes in a cave or in a
  cave or solution-sculptured rock. A
  complex of many irregular and repeatedly
  connected passages[9>21]. Synonym:
  labyrinth; (French.) anastomose;
  (German.) Labyrinth; (Greek.)
  anastomosis; (Italian.) anastomosi;
  (Russian.) labirint; (Spanish.)
  anastomosis; (Turkish.) gegit §ebekesi;
  (Yugoslavian.) splet kanala.

anastomotic cave pattern. A type of maze
  cave consisting of tubular passages or
  holes in a cave or in a solution-sculptured
  rock. A complex of many irregular and
  repeatedly connected passages.
  Synonym: labyrinth.

anchor. A fixed object used to secure a
  man whilst operating a safety rope or for
  attaching equipment such as ladders or
  ropes[25].

anchor ice, ground ice. Ice that is
  temporarily attached to the bottom of a
anemolite. A helictite in which the
  eccentricity is ascribed to the action of air
  currents1101. The word is derived from
  wind-control theory of helictite
  formation[9].

anemometer. A device used to measure
  wind speeds[16].

angle of contact, wetting angle.  The angle
  between the liquid phase and solid
  boundary measured through the liquid
  phase[16].

angle of repose. The natural slope of
  unsupported granular material1163.

anglesite.  A cave mineral — PbSO4[11].

angular. The property of unconsolidated
  grains with sharp edges[16].

angular unconformity. A geological
  unconformity with marked difference in
  dip of the superimposed series[16].

anhydride. Anhydrous calcium sulfate,
  CaSO4[16].

anion. A negatively charged ion that
  migrates to an anode, as in electrolysis[6].

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anion exchange.  Ion exchange process in
  which anions in solution are exchanged
  for other anions from an ion exchanger161.

anisotropic.  The property of aquifer
  systems displaying different hydrological
  properties in different directions1161. See
  also anisotropy; anisotropic mass.

anisotropic mass. A mass having different
  properties in different directions at any
  given point[22].

anisotropic steering. Anisotropic
  structures (anisotropies) in the rock like
  schistosity, inclusions and fractures which
  can deviate or 'steer' the direction of
  fractures subsequently developed.

anisotropy. The condition of having
  different properties in different
  directions1221.

annual frost zone. The top layer of ground
  subject to annual freezing and thawing[I6].

annual mean.  The mean value taken over
  all events that have occurred during a year
  such as precipitation, river stages, water-
  table levels'161.

annulus.  The annular space between drill
  pipe and casing or between casing and the
  borehole wall[16].

anomaly. The deviation from normally
  expected findings, especially in
  exploration geophysics indicating a
  change in subsurface environmental
  conditions^161.
antecedent precipitation index. A
  precipitation index that is based on the
  amount of previous precipitations1^61.

antecedent-soil moisture.  The degree of
  water saturation in the soil prior to a
  precipitation event116].

antecedent stream.  A stream having
  established its course before occurrence
  of orogenic events that would later alter
  the general drainage patterntl6].

antenna (plural antennae).  A feeler; an
  appendage, sensory in function, that
  occurs in pairs on the heads of
  crustaceans, insects, and certain other
  animals[23].

anthodite. 1. Radiating crystals of
  aragonite, mostly sharp needles 1-20 mm
  long. They occur sporadically in some
  caves but they may also be spectacularly
  abundant, with clean white crystals
  growing all over the rock and calcite
  surfaces. Carlsbad Caverns (USA) and
  Grotte de Moulis (France) have fine
  anthodite displays[9]. 2. A cave formation
  composed of feathery or radiating masses
  of long needlelike crystals of gypsum or
  aragonite, which radiate  outward from a
  common base[10]. See  also cave flower.

anthropocentric definitions. Definitions of
  caves or parts of caves that include
  accessibility by human explorers as one of
  their limiting conditions. Most well
  known among these is the definition
  published by the International
  Speleological Union, that 'A cave is a
  natural underground opening in rock that
  is large enough for human entry' (see
  proto-caves)[9].
                                             10

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anticlinal valley. A valley that is
   established along the axis of an eroded
   anticline1161.

anticline. Upfolded stratum[I6].

aphthitalite. A cave mineral —
   (K,Na)3Na(S04)2[111.

apparent ground-water velocity.  See
   specific discharge.

appendage. An arm or other limb that
   branches from an animal's body[23].

approach segment. That part of a
   hydrograph curve before onset of
   precipitation[I6].  See also hydrograph.

apron. A smooth bulging mass of
   fiowstone covering sloping projections
   from walls of caves or limestone cliffs1101,

aquatic.  Living in water. Aquatic cave
   animals include amphipods, isopods,
   crayfish, planarians, fish, and blind
   salamanders1231. See also terrestrial;
   marine.

aqueduct. A conduit to convey water,
   usually above ground1161.

aquiclude. A formation which, although
   porous and capable of storing water, does
   not transmit it at rates sufficient to furnish
   an appreciable supply for a  well or spring.
   See also confining unit[22].

 aquifer.  1. A formation, group of
   formations, or part of a formation that
   contains sufficient saturated permeable
   material to yield significant quantities of
   water to wells and springs161.  2. A
  ground-water reservoir.  3. Pervious rock
  that is completely saturated and will yield
  water to a well or spring. Historically the
  term has been applied to beds favoring
  early cave development, probably
  synonymous with some inception
  horizons[18].

aquifer, artesian.  A confined aquifer
  where the potentiometric surface rises
  above the top of the aquifer bed[16].

aquifer, coastal. An aquifer in a coastal
  region open to salt-water intrusions1161.

aquifer, flowing artesian.  An artesian
  aquifer in which the water, under
  hydrostatic pressure rises above the land
  surface.

aquifer, karst. An aquifer in which the
  flow of water is or can be appreciable
  through one or more of the following:
  joints, faults, bedding-plane partings, and
  cavities — any or all of which have been
  enlarged by dissolution^81.

aquifer, leaky.  An aquifer overlain or
  underlain by semipermeable strata from
  or into which water will flow[16].

aquifer stimulation. A type of
  development that is done in
  semiconsolidated and completely
  consolidated formations to alter the
   formation physically to improve its
  hydraulic properties161.

aquifer storage. Gas storage in an
   aquifer[16].

aquifer system. A body of permeable and
   poorly permeable material that functions
                                             11

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  regionally as a water-yielding unit; it
  comprises two or more permeable beds
  separated at least locally by confining
  beds that impede ground-water movement
  but do not greatly affect the regional
  hydraulic continuity of the system;
  includes both saturated and unsaturated
  parts of permeable material1221.

aquifer test.  A test to determine hydrologic
  properties of the aquifer involving the
  withdrawal of measured quantities of
  water from or addition of water to a well
  and the measurement of resulting changes
  in head in the aquifer both during and
  after the period of discharge or
  additions161.

aquifere epikarstique. See epikarst zone.

aquifuge.  A formation which has no
  interconnected openings or interstices and
  therefore neither stores nor transmits
  water[22]. See also confining unit.

aquitard.  A confining bed that retards but
  does not prevent the flow of water to or
  from an adjacent aquifer; a leaky
  confining bed. It does not readily yield
  water to wells or springs, but may serve
  as a storage unit for ground water[22]. See
  also confining unit.

aragonite. 1. A relatively rare form of
  calcium carbonate (CaCO3), chemically
  identical to the more common calcite but
  of orthorhombic crystal form. Its pure
   form is metastable in the cave
   environment, where calcite forms
  preferentially. It is relatively abundant in
   some caves due to the presence of
   impurities, notably strontium, that distort
  the carbonate lattice and favor aragonite
  growth. The commonest form seen in
  caves as small radiating crystals
  (anthodites) that develop in humid caves,
  where surfaces are covered by a moisture
  film but not by flowing water. 2. A
  mineral composed of calcium carbonate,
  CaCO3, like calcite but differing in crystal
  form[10]. 3. An unstable orthorhombic
  carbonate mineral, CaCO3[16].

ardealite. A cave mineral —
area of influence of a well. The area
  surrounding a pumping or recharging well
  within which the potentiometric surface
  has been changed[22].

arete and pinnacle karst. A landscape of
  naked reticulated raw-topped ridges
  having almost vertical slopes and a relief
  of as much as 120 meters. The ridges rise
  above forest- covered corridors and
  depressions.  Found in New Guinea at
  elevations of 2,000 meters and more[10].
  Both pinnacle karst and arete karst are
  varieties of limestone landscape formed
  under equatorial rain forest cover.  They
  are characterized by vertical sided blades
  of bare rock fretted by dissolution191.

argillaceous. The property of rocks
  containing clay in non-negligible
  proportions[16].

argillaceous limestone. Limestone
  containing considerable amounts of
  clay!161.

arid. The property of dry climates and
  regions with a net deficiency of
  moisture[161.
                                             12

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arrival time. 1. The time of arrival in
   subsurface flow tracing for the first tracer
   pulse to arrive at a discharge location. 2.
   The time of arrival in geophysics for the
   first seismic wave to arrive at a
   geophone[16].

artefact A product of human manufacture
   or art, e.g. tools of bone, stone, etc.,
   paintings, engravings. In caves, tools are
   often buried in sediment. (Scientific
   attention should be drawn to the finding
   of artefacts in caves'251.)

artesian. Synonymous with confined.

artesian aquifer. Synonymous with
   confined aquifer.  See aquifer, artesian.

artesian flow. Flow through a confined
   aquifer where the elevation of the
   overlying aquiclude is locally depressed
   so that the entire aquifer is saturated and
   the flow is under hydrostatic pressure.
   Some maze cave development in
   cavernous limestones may be due to
   artesian flow, which is commonly related
   to synclinal fold structures'93.

artesian spring.  See spring, artesian.

artesian well. A well deriving its water
   from a confined aquifer in which the
   water level stands above the ground
   surface[5].  Synonym: flowing artesian
   well.

arthropods.  Animals with jointed legs and
   bard external skeletons (exoskeletons).
   The group includes insects, crustaceans,
   spiders, millipedes, and several other
   types of animals commonly found in
   caves'231.
artificial discharge. The discharge of
  ground water by pumping wells'161.

artificial recharge. Recharge at a rate
  greater than natural, resulting from
  deliberate or incidental human
  activities'61.

ascender. A mechanical device used by
  cavers who are either ascending or are
  descending through a vertical opening in
  a cave (e.g. vadose shaft) that uses a cam
  to grip a rope while downward pressure is
  being applied to the device'131. See also
  mechanical ascender; prusiking; prasik
  knot.

association.  A relatively stable community
  of different species living in a
  characteristic habitat'251.

atmometer.  An instrument used to measure
  evaporation intensities'161.

atmosphere. A gaseous envelope of the
  earth that contains and transports air and
  water in vapor and condensed form'161.

attapulgite clay.  A colloidal, viscosity-
  building clay consisting of hydrous
  magnesium aluminum silicates and used
  principally in salt-water drilling fluids'61.

attrition. The wearing away of rocks by
  friction'161.

auger. A rotary drilling device where the
  dry cuttings are removed continuously by
  helical grooves on the drill pipe'161.

aurichalcite. A cave mineral —
  (Zn,Cu)5(C03)2(OH)6.
                                             13

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autochthonous. Property pertaining to
  sedimentary material originating and
  deposited at about the same location1161.
  See also allochthonous.

autochthonous drainage. Less common
  synonym for autogenic drainage[91.

autogenic, authigenic. Formed or
  generated in place[1]. See also allogenic;
  recharge, autogenic; recharge, allogenic.

autogenic drainage. Underground karst
  drainage that is derived entirely by
  absorption of meteoric water into the
  karst rock surface191. Synonym:
  autochthonous drainage.  See also
  allogenic drainage.

available water. The water available to
  plants in the soil zone as defined by the
  interval between field capacity and
  wilting point[16].

aven. 1. A hole in the roof of a cave
  passage that may be either a rather large
  blind roof pocket or a tributary inlet shaft
  into the cave system.  A feature described
  as an aven when seen from below may
  equally be described as shaft when seen
  from above, and the naming of such a
  feature commonly depends purely upon
  the direction of exploration. Many avens
  close upwards to impenetrable fissures
  but may still be important hydrological
  routes; few caves are without them. In
  parts of France, aven is equivalent to the
  British term, pothole[9]. 2. (French.) A
  vertical or highly inclined shaft in
  limestone, extending upward from a cave
  passage, generally to the surface; smaller
  than an abime. Commonly related to
  enlarged vertical joints. Compare cenote;
  natural well; pothole. 3. (British.) A
  vertical extension from a shaft in a
  passage or chamber roof that tapers
  upward rather like a very elongate
  cone[10].  Compare dome pit.

average interstitial velocity.  See velocity,
  average interstitial.
azimuth.  The true bearing of a survey line,
  determined by measurement from an
  accurate survey or by observations of sun
  or stars[25].

azonal soil. Soils without distinct layering
  in horizons1'61.

azurite. A cave mineral —
  Cu(CO3)2(OH)2[11].
                                             14

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                   B
backflooding. 1. Temporarily rising water
   level in a cave caused by downstream
   passage being too small to pass an
   abnormally high discharge. The
   excavation and reexcavation of some
   caves is ascribed to the enlargement of a
   passage at or near the water table by
   gravity flow alternating with periods of
   calcite precipitation1101. 2. Flooding due
   to backup of excess flow behind a
   constriction in a major conduit.  Water
   that is ponded in tributary passages and
   proto-caves upstream of the constriction
   may contribute to the enlargement of
   maze caves[9].

background noise. The level of intensity of
   signals due to normal activities other than
   the specific signal emission[16].

backwater. The accumulated water above
   the normal level of a water course due to
   impoundment at a point downstream[161.

backwater curve. Water surface profile in
   a stream or channel above a constriction
   or impoundment^61.

bacon. Thin, elongated, translucent
   flowstone having parallel colored bands
   on or projecting from roofs and walls of
   some caves[IO].  See also blanket; curtain;
   drapery.

 bacteria.  Simple, colorless one-cell plants,
   most of which are unable to manufacture
   their own food using sunlight Bacteria
   are possibly important in caves as
   synthesizers of food materials from
   minerals. They are also important as
   decomposers1231.
bactericide. A substance used to destroy
  bacteria (e.g. iron bacteria)[6].

bailer.  1. A cylindrical container used to
  withdraw a sample of water from a well.
  2. A cylindrical container with a bottom
  valve for the clearing of drill cuttings
  from the bottom of a borehole[16].

bailing line. Cable operating a bailer[16].
  Synonym: sand line.

balcony.  Any proj ection on the wall of a
  cave large enough to support one or more
  persons1101.

bank. Ascending slope bordering a river[16].

bank erosion. Erosion of a river bank[16].

bank storage. 1. Subsurface conduit water
   that has been driven back up into older,
   higher karst levels and into the
   surrounding rock matrix during a high
   flow period. 2. River water that has
   infiltrated river banks during a high flow
   period  and being retained in temporary
   storage1161.

barbels.  Fleshy threadlike sensory
   structures hanging like whiskers near the
   mouths of certain fish, such as catfish[23].

bare karst. A type of karst landscape
   lacking soil cover and where dissolution
   of carbonate rocks to form karst
   landforms occurs primarily on the
   exposed bedrock surface[9]. See naked
   karst.

 barite. 1. A cave mineral — BaSO4. 2. A
   natural finely ground barium sulfate  used
                                             15

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   for increasing the density of drilling
   fluids161.

barograph. A pressure recordedI6].

barometer. An indicator of barometric
   pressure1'61.

barometric efficiency.  The ratio of water
   level change to atmospheric pressure
   change in a well[16].

barrier. A geological formation or part of a
   formation having become impervious to
   ground-water flow due to a facies
   change1161.

barrier, freshwater.  Barrier of freshwater
   injected into an aquifer to stop the inflow
   of seawater into a coastal aquifer^161.

barrier, hydrologic. Lithologic formation
   preventing horizontal movement of
   ground water1-161.

barrier, permeability.  A geologic or
   petrographic feature in a bed obstructing
   free flow[16].

barrier spring. See spring, barrier.

base exchange. The displacement of a
   cation bound to a site on the surface of a
   solid, as in silica-alumina clay-mineral
   packets, by a cation solution161.

base flow. 1. That part of the stream
   discharge that is not attributable to direct
   runoff from precipitation or melting
   snow; it is usually sustained by
   ground-water discharge1221.  2. Sustained
   fair weather runoff1161.
base level. Lowest level of erosion by a
   stream[16].

base level of erosion.  The lowest
   theoretical level of surface to be achieved
   by erosion[16].

base level, karst. See karst base level.

base line.  1. An arbitrary line from which
   deflections of self potential are read[16]. 2.
   Shale line[16].

baseline monitoring.  The establishment
   and operation of a designed surveillance
   system for continuous or periodic
   measurements and recording of existing
   and changing conditions that will be
   compared with future observations^21.

base of karstification. Level below which
   karstification has not occurred. See also
   karst base level.

base width. The width of the hydrograph as
   determined by a line parallel to the time
   axis cutting through the points where the
   rising limb starts and where the recession
   curve ends[16].

basin.  Hydrogeographic unit receiving
   precipitation and discharging runoff in
   one point[161.

basin characteristics.  The physiographic,
   geologic, and ecologic characteristics of a
   basin[16].

basin, closed. Drainage basin with no
   surface flow outlet[16].
                                             16

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 basin, drainage.  The area contributing to
    runoff which sustains streamflow[16]. See
    also drainage basin.                "

 basin, experimental.  A basin chosen for
    the thorough study of hydrological
    phenomena[I6].

 basin, ground-water. The area throughout
    which ground water drains towards the
    same point. It can be larger than the
    associated drainage basin if permeable
    layers extend outside of the topographical
    divide[I6]. In karst terranes, the ground-
    water basin often does not resemble the
    drainage basin.

 basin, infiltration. Basin in which water is
    spread for recharge[I6].

 basin, intermontane. A basin lying
   between two mountain ranges[16].

 basin method. A recharge method in which
   water is spread in shallow basins[I6].

 basin mouth. The point at which runoff
   leaves a basin[16].

 basin perimeter. The circumference of a
   basin following the divide[16].

 basin relief, maximum. The elevation
   difference between basin mouth and the
   highest point within a basin perimeter[16].

basin, settling. A basin used for the settling
   out of solids from suspension1161.

bat. A member of the order Chiroptera, the
   only mammals capable of true flight as
   they have membranes between the toes of
   their forefeet[25].
 bathybenthic.  Of the bottom of the truly
    .deep areas of the sea, where the "rain" of
    organic material produces a deposit of
    food!231.

 bathypelagic. Of the deep sea.  Refers to
    the depths between roughly 3000 feet
    below the surface and the bottom of the
    sea. No food accumulates in these
    waters[23].

 bathyphreatic. Referring to water moving
    with some speed through downward
    looping passages in the phreatic zone[25].
    See bathyphreatic zone, ground water,
 •   phreas.

 bathyphreatic zone.  See bathyphreatic,
    ground water, phreas.

 bathometer. An instrument for measuring
   water depths in wells[16].

 beach.  A shore consisting of sand or gravel
   deposits[16].

 beachrock. 1. Rock composed of sand
   grains and/or sand-sized shell fragments
   cemented by calcium carbonate,
   commonly formed very rapidly on some
   beaches in tropical and sub-tropical areas.
   Beachrock generally occurs as thin beds
   between bedding planes that dip seawards
   at angles similar to those of the beach
   slope[9]. 2. A friable to indurated rock
   consisting of sand grains of various
   minerals cemented by calcium carbonate;
   occurs in thin beds dipping seaward at
   less than 15o. Also known as beach
   sandstone[10].

bearing. The angle measured clockwise
   that a line makes with the north line.
                                            17

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  True, magnetic and grid bearings are
  measured respectively from true,
  magnetic and grid north[25].

bed. 1. A layer in sedimentary rocks; a
  stratum1101. 2. A sedimentary deposit of
  relatively small thickness and great areal
  extent, separated by bedding planes from
  over- and underlying deposits[16].

bed load. Seebedload.

bed, lower confining. An impermeable bed
  underlying an aquifer[16].

bed, marker.  Bed with characteristic
  features that can be followed over large
  areas for identification purposes1161.

bed, mortar.  Secondary calcium carbonate
  cementations in the lower part of a soil
  profile1161. Synonym: hardpan.

bed, river.  The channel of a river covered
  by water*163.

bed roughness.  The roughness of a channel
   or river bed[16].

bed, stream.  The bottom of a stream
   covered by water[16].

bed, upper confining. Impermeable bed
   overlying an aquifer[16].

bedding. Applies to rocks resulting from
   consolidation of sediments and exhibiting
   surfaces of separation (bedding planes)
   between layers of the same or different
   materials (e.g., shale, sandstone,
   limestone, etc.).

bedding cave. See bedding-plane cave.
bedding grike. Term used to describe the
  occurrence of the dissolution and
  widening (similar to that which occurs in
  joints) of nearly vertical bedding in karst
  terranes[8].  Synonym: (German.)
  Schichtfugenkarren.

bedding joint.  A joint in rocks that runs
  parallel to or on a bedding plane[16].

bedding plane.  1. A primary depositional
  lamination in sedimentary rocks that may
  be preserved, though possibly with
  different properties, in metamorphic
  rocks. These laminations may be clearly
  visible where lithologies change or where
  depositional cycles were
  completed/initiated, or they may be
  effectively invisible to the naked eye,
  marking subtle changes in depositional
  conditions. Most bedding planes were
  originally horizontal or very slightly
  inclined, but more steeply inclined
  bedding planes developed in rocks
   deposited in deltaic or sand dune
   environments or in marine reefs. When
  rocks are folded the bedding planes
   provide an indication of the degree of
   deformation.  Bedding planes play a
   crucial role in the inception and ongoing
   development of most caves and many
   surface karst features131. 2. A plane that
   separates two strata of differing
   characteristics1101. See also parting.

 bedding-plane cave. 1. Bedding planes are
   widespread and very significant features
   within most carbonate rocks, and cave
   passages are commonly guided by them.
   Their structure, their distribution and the
   chemical contrasts that some bedding
   planes provide may be the major
   influence during the earliest phases of
                                             18

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  development of a cave system. The term
  bedding-plane cave is strictly applied to a
  passage that has not enlarged by growth
  into a major tube or canyon, but has
  remained almost entirely on the bedding
  plane.  A famous example is Hensler's
  Passage, in Gaping Gill, Yorkshire, which
  is over 400 m long, nearly over 5 m wide
  and nowhere higher than 1 m[9]. 2. A
  passage formed along a bedding plane,
  especially when there is a difference in
  susceptibility to corrosion in the two
  beds[10].  3. A cave whose location is
  controlled by the bedding of the enclosing
  formation or formations^01. Synonyms:
  (French.) grotte de stratification;
  (German.) schichtgebundene Hohle;
  (Greek.) strosigenes spelean; (Italian.)
  grotta di interstrato; (Russian.) pescera v
  ploakosti naplastovanija; (Spanish.) cueva
  adaptada a pianos de estratificacion;
  (Turkish.) tabakalanma magarasi;
  (Yugoslavian.) slojna pecina.

bedding-plane parting.  See bedding plane
  and parting.

bedeckter karst. See covered karst.

bedload.  The part of the total stream load
  that is moved on or immediately above
  the stream bed, such as the larger or
  heavier particles (boulders, pebbles,
  gravel) transported by traction or saltation
  along the bottom;  the part of the load that
  is not continuously in suspension or
  solution[6].

bedrock.  Solid rock underlying
  unconsolidated material[16].

bench mark.  A relatively permanent mark,
  natural or artificial, furnishing a survey
  point at a known elevation in relation to
  an adopted datum[16J. Bench marks, or
  marked points, connected by precise
  leveling, constitute the control of land-
  surface settlement in subsidence
  studies1211.

bend.  Curve in a water course'161.

bentonite. A colloidal clay, largely made up
  of the mineral sodium montmorillonite, a
  hydrated aluminum silicate'61.

B-horizon. Illuvial horizon in which
  soluble material from the overlying A-
  horizon has been deposited1161.

belay. A safety rope tied around a caver that
  is played out or taken in by a second
  person as the caver moves. The purpose
  of the belay is to prevent the caver from
  falling more than a few feet[13].

beudantite. A cave mineral —
  PbFe3(As04)(SO4)(OH)6[11].

bicarbonate.  A salt containing the radical
  HCCV1, such as Ca(HCO3)2[10].

bifurcation.  The forklike separation of a
  water course into two arms[16].

bifurcation ratio. The ratio of the number
   of stream segments of a given order to the
   number of segments of next higher
   order[16].

biological clock. An inherited time-
   measuring process within a living thing,
   which governs its responses to certain
   external events1231.
                                             19

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biomass.  The total weight of living matter,
  whether in an entire community, at a
  particular trophic level, or of a particular
  kind of organism in the community.  Thus
  we may refer to the biomass of a pond
  community, of herbivores hi the pond, or
  of copepods in the pond[23].

biomicrite.  A microscopic-textured
  limestone composed of skeletal grains in
  a matrix of micrite; micrite is a finely
  crystalline carbonate sediment with the
  upper crystalline diameter being 4
  microns[20]. Synonyms: (French.)
  biomicrite; (German.) Biomicrite; (Greek.)
  micrite; (Italian.) biomicrite; (Spanish.)
  biomicrita; (Turkish.) biyomikrit;
  (Yugoslavian.) biomikrit. See also
  micrite; peloid.

biospeleology.  1. The study of subterranean
  living organisms, particularly in karst
  caves and other openings in rock
  formations19'211. 2. The scientific study of
  cave animal life, or the biology of caves,
  karst, and groundwater. A biologist who
  specializes in this study is called a
  biospeleologis't[23].  Synonyms: (French.)
   biospeleologie, biospeologie; (German.)
  Biospelaologie; (Greek.) biospeleology;
   (Italian.) biospeleogia; (Russian.)
   biospeleologija; (Spanish.)
   biospeleologia; (Turkish.) biyospeleoloji,
   magara canlilan bilimi; (Yugoslavian.)
   biospeleologija.

biphosphammite. A cave mineral —
   NH4H2PO4[n].

birnessite.  A cave mineral —
   (Na,Ca)Mn7O14-3H2Otll].
blade. In a cave, a thin sharp projection
  jutting out from roof, wall, or floor, of
  which it is an integral part; generally the
  remains of a partition or bridget101.

blanket. A thick layer of dripstone, not
  translucent[10]. See also bacon; curtain;
  drapery.

blind chimney.  See chimney.

blind shaft. A vertical extension upwards
  from part of a cave, but not reaching the
  surface; small in area in relation to its
  height1251.

blind valley.  1. A karst valley abruptly
  terminated by the passage underground of
  the watercourse which has hitherto
  resisted the karst processes and remained
  at the surface. An intermediate type, the
  half-blind valley, exists in which the
  valley form continues downstream from
  the sinkhole used under conditions of
  normal river flow. The watercourse .only
  flows here intermittently and the valley
  may (except for its use as a flood conduit)
  be fossil in that it represents the section
   abandoned by the river as it sought
  progressively higher swallow holes[I9].  2.
  A karst valley with no evident
   downstream continuation, and one in
  which the water drains and disappears
   underground into one or more ponors[20].
   3. A valley that terminates abruptly at a
  point where its stream sinks, or once
   sank, underground. As sinks develop
   higher up the blind valley, the original
   valley termination may be dry under most
   flow conditions191. Related to marginal
   polje. Synonyms: (French.) vallee
   aveugle;  (German.) Blindtal, (Kesseltal);
   (Greek.) kliste karstike Mas; (Italian.)
                                             20

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  valle cieca, valle chiusa; (Russian.)
  slepaja dolina; (Spanish.) valle ciego;^
  (Turkish.) kor vadi; (Yugoslavian.) slijepa
  dolina, sepa dolina. See also half-blind
  valley; marginal polje.

bloedite. A cave mineral —
  Na2Mg(S04)2-4H2)[11].

blowhole.  1. Opening in the roof of a cave
  or cavern through which air is expelled
  vigorously.  In coastal areas the
  phenomenon is usually due to
  compression of air within the cave by
  incoming tides or waves[20]. 2. Cliff top
  entrance to a sea cave, also known as a
  geo, gloop, or gloup[9].  3. (Australian.) A
  small hole in the surface of the Nullarbor
  Plain through which air blows in and out
  with observable  force, sometimes
  audibly^. Related to breathing hole.
  Synonyms: (French.) trou souffleur;
  (German.) Windhohle; (Greek.) ope
  ekphysosa; (Italian.) bocca soffiante;
  (Spanish.) soplador; (Turkish.) uflenme
  agzi; (Yugoslavian.) vjetrenica, veternica,
  puhaljka, pihalnik, dihalnik. See also
  steam hole.

blowing cave. A cave out of which or into
  which a current of air flows
  intermittently1103.

blowing well.  A well or borehole into
  which air is sucked and from which air is
  blown (often with considerable velocity)
  due to changes in barometric pressure or
  in water level. The phenomenon
  indicates that the well or borehole is in
  communication with an underground air-
  filled cavity. Synonyms: (French.) puits
  souffleur; (German.) Windkamin; (Greek.)
  ekphysosa ope; (Italian.) pozzo soffiante;
  (Russian.) dujuscij kolokec; (Spanish.)
  sondeo soplador; (Turkish.) iiflec kuyu.
  See also steam hole.

blowout. An uncontrolled escape of drilling
  fluid, gas, oil, or water from a well caused
  by the formation pressure being greater
  than the hydrostatic head of the fluid in
  thehole[6].

blue hole. 1. Deep resurgence pool, notably
  in Jamaica and Florida, that may have a
  blue color due to the presence of algae.
  Also a deep submarine cave of the
  Bahamas. The latter type are large
  flooded shafts cut into the limestones of
  the shallow reefs and lagoon floors.
  Many are 100 m in diameter and some are
  100 m deep.  Opening from the shafts are
  flooded cave passages at various depths,
  some of which have been explored
  subhorizontally for more than 1 km.
  Their origins are complex. Extensive
  stalagmite deposits show that large old
  caves were drained when sea-levels were
  low during the Pleistocene (when water
  was held in the ice sheets). They are now
  being modified by marine dissolution,
  notably at the interface between fresh and
  salt waters (sea littoral zone) and by
  powerful tidal flows between connected
  holes[9]. 2. (Jamaican.) A major emer-
  gence where water (artesian spring) rises
  from below without great turbulence. 3.
  (Bahamas.) A drowned solution
  sinkhole[10]. 4. Caribbean expression for a
  major quiet up-welling karst spring inland
  or along the coast. The blue color is due
  to the scattering of sunlight by water
  molecules, although in some cases it may
  be attributed to the presence of calcareous
  algae[20]. Synonyms: (French.) source
  bleue (Jura), bleu-fon (South of France);
                                            21

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   (German.) Blaue Grotto; (Greek.) galapo
   speleo. See also boiling spring.

bobbin.  A decender that opens to enclose
   the rope around two fixed pulleys. May
   have a handle ("STOP") which must be
   squeezed to allow descent'251.

Bodenbedeckter karst. See subsoil karst.

bog. Swamp[16].

bogaz. 1. (Slavic.) An elongated depression
   in limestone or karst terrain; thus it
   embraces a defile, a blind valley or a
   ravine leading to a ponor. It can be
   considered as a giant grike. This meaning
   is based on the Serbian use[20]. 2. A
   variable-discharge artesian spring in
   which hydrostatic pressure is great
   enough to cause a turbulent or even
   fountain-like discharge. 3. A long narrow
   chasm enlarged by solution of the
   limestone1'01.  4. Large linear fissure or
   box valley through a karst block.
   Effectively a giant grike, perhaps 50 m
   deep and 1 km long, formed by
   dissolution on a fault or joint in very
   massive limestone191.  Synonyms:
   (French.) defile, bogaz; (German.) Doline,
   Karstgafie, Blindtal, Zangon; (Greek.)
  faragotliis doline; (Spanish.) zanjon;
   (Turkish.) bogaz; (Yugoslavia.) bogaz.
   See also canyon; gorge; grike; corridor;
   struga; zanjon.

boiling spring. See spring, boiling.

bollard.  A projection of rock over which
   rope, tape or wire can be placed to create
   an anchor1251.
bolt.  A high tensile steel bolt used as an
   anchor; either a conical bolt screwed into
   a metal holder in a hole drilled in rock,
   causing expansion for grip, or a bolt with
   partially filed thread hammered into a
   slightly smaller hole[25].

bone-breccia.  1. Cave breccia including
   much bone[IO].  2. A breccia containing
   many bone fragments.  (Scientific
   attention should be drawn to the finding
   of such in caves[25].)

bone cave. A cave recognized particularly
   for its contained deposits of animal bones.
   The bones may be the remains of animals
   that fell into the cave, as in the Joint
   Mitnor Cave, Devon, or in many other
   pitfall or fissure sites. Alternatively the
   bones maybe of animals that originally
   lived in the cave — and these may
   include man, as at Niah Cave, Sarawak,
   or at Russell  Cave, USA.  A third, and
   most important, type of bone cave is the
   ancient animal den, into which scavengers
   such as hyaenas dragged the remains of
   many other animals,  as for example at
   Kirkdale Cave in North'Yorkshire'31.

borehole.  1. Boring into unconsolidated
   and consolidated materials for the
   purpose of subsurface hydrogeological
   investigations.  2. Synonym for a well
   developed phreatic tube passage'91.

botryoid, botryoidal speleothem. 1.
   Generally sub-spherical or globular
   calcium carbonate deposits ranging in
   size between tiny beads and masses up to
   1 m across. Botryoidal describes a form
   resembling a bunch of grapes[9]. 2. A
   grape-like deposit of calcium carbonate
   generally found on walls of caves'101.
                                            22

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   Synonyms: clusterite; grape formation.
   See coralloid speleothem.
                                     >.
bottom hole. The lowest part of a drilled
   hole where the drilling bit cuts into the
   rock'161.

bottomland. A lowland along an alluvial
   river plain'161.

boulder clay.  See glacial till.

boundary spring. See spring, boundary.

bourne.  (British.) 1. A stream that appears
   in a normally dry valley, particularly on
   the Chalk outcrop in southern England,
   during wet conditions'91. 2. Intermittent
   stream in a normally dry valley in chalk
   country1103.

boxwork.  1. A three-dimensional network
   of thin sheets of mineral projecting from a
   cave wall. The boxwork is vein fillings
   etched from the cave wall by dissolution
   of the host limestone and consists mostly
   of calcite and quartz.  It is not common,
   but spectacular displays occur in Ind
   Cave, South Dakota, USA[9]. 2. Network
   of thin blades of calcite or gypsum etched
   out in relief on the limestone walls and
   ceiling of a cave'101.

brackish water. Water containing from
   1000 to 10,000 ppm of total dissolved
   solids'161.

braided stream.  A stream that divides into
   or follows an interlacing or tangled
   network of several small branching and
   reuniting shallow channels separated
   from each other by branch islands or
  channel bars, resembling in plan the
  strands of a complex braid'61.

brake bar. A round bar approximately
  x % inches that is placed on rappel racks
  or carabiners so that rope can be threaded
  through the rack or carabiners for
  rappelling'131.

branchwork cave pattern. 1. A cave
  system that has been formed by the
  intersection of tubular or canyon-like
  conduits as tributaries in the down-flow
  direction. 2. A dendritic cave system of
  subterranean watercourses having many
  incoming branches and no visible
  outgoing ones[IO].

breakdown.  See cave breakdown.

breakthrough.  A quantum jump in
  erosional activity that is associated with
  the transition from dommantly laminar to
  dominantly turbulent flow conditions'91.
  See turbulent threshold.

breakthrough curve. 1. A plot of relative
  concentration versus time, where relative
  concentration is defined as C/Co with C
  as the concentration at a point in the
  ground-water flow domain, and Co as the
  source concentration1221. 2. A plot of
  tracer concentration, C, versus time, t, for
  a ground-water tracing study in karst
  conduit for the purpose of quantitatively
  determining how much tracer mass was
  recovered,  mean time of travel, mean
  tracer flow velocity, and related hydraulic
  flow and geometric parameters.
  Synonyms: recovery curve; tracer-
  breakthrough curve; tracer-recovery
  curve.
                                            23

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breakthrough time.  The time required to
   develop a conduit large enough (usually
   5-10 mm in diameter) to support
   turbulent flow[9].

breathing cave. Air movement through a
   cave is described as breathing when it
   reverses more frequently than the
   seasonal reversal of a through-draught in
   a cave with higher and lower entrances.
   Slow breathing occurs in response to
   barometric pressure changes, when the
   volume of cave air is forced to change. It
   is notoriously strong in large caves of the
   Australian Nullarbor Plain. More rapid
   wind reversals or oscillations, as in
   Breathing Cave, Virginia, are a resonance
   phenomenon, similar to the effect
   produced by air passing over the neck of a
   bottle. In the cave environment the
   resonant frequency is relatively low and
   periodic air flow reversals occur, rather
   than the sound waves observed at the
   higher frequencies met in the bottle neck
   example191.

breathing hole. Opening in the roof of a
   cave, cavern or other underground void
   through which air is sucked in and
   expelled in a rhythmic manner similar to
   inhalation and exhalation of breath[20].
   Related to blow hole and steam hole.
   Synonyms: (French.) trou souffleur;
   (German.) Luftloch, (Greek.) anapneousa
   opi spileon; (Spanish.) respirador;
   (Turkish.) esintili delik.

breccia. 1. Angular fragments of rock,
   commonly, but not inevitably, cemented
   by finer-grained materials including
   silica, iron minerals, and calcite to form a
   new rock. Many fault planes are marked
   by zones of broken rock, either loose or
  re-cemented, forming a fault breccia[9]. 2.
  Rock composed of angular fragments1161.

bridge. 1. May be a natural bridge of
  bedrock normally formed outside a cave
  entrance by partial collapse leaving an
  isolated roof segment, as in the famous
  examples of Rakov Skocjan, Slovenia.
  Rock bridges may also occur inside caves
  due either surrounding phreatic
  dissolution or collapse between
  superimposed passages. Another
  common type inside a cave is a span of
  false floor where sediment is washed
  from below, as at The Bridge in GB
  Cavern in the Mendip Hills[9]. 2. hi a
  cave, a residual rock span across a
  passage1101.  3.  hi water wells, an
  obstruction in the drill hole or annulus. A
  bridge is usually formed by caving of the
  wall of the well bore, by the intrusion of a
  large boulder,  or by filter pack materials
  during well completion. Bridging can
  also occur in the formation during well
  development1161. See also natural bridge.

bridging effect.  The forming of arches in a
  packing of materials1161.

brine. Water containing more than 100,000
  ppm of total dissolved solids1161.

brittle deformation. The sudden failure of
   a rock with complete loss of cohesion
   across a plane.

brochantite. A cave mineral —
   Cu4(S04)(OH)6t11].

brushite. A cave mineral—   •
.   CaHPCy2H2O[111.
                                            24

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bubble gage.  A stage recorder based on the
   principle of equating a gas pressure tq,
   water level[16].

bucket. A measuring reservoir in liquid
   gaging instruments1163.

buffered solution. A solution that resists
   changes in the pH value upon addition of
   acids or bases[16].

buildup. The vertical distance the water
   table or potentiometric surface is raised,
   or the increase of the pressure head due to
   the addition of watert22].

buried karst. Karst topography entirely
   buried by relatively younger post-rock or
   sediments and not part of the
   contemporary landscape[17]. Synonyms:
   fossil karst; (French.) karst convert, karst
  fossile, paleokarst; (German.) bedeckter
   Karst, Urkarst; (Greek.) kaymeno
  paleokarst; (Italian.) carso sepolto;
   (Spanish.) karst soterrado; (Turkish.)
   gdmillu karst; (Yugoslavian.) pokriveni krs
   See also covered karst; paleokarst; subsoil
   karst.

buried valley.  An ancient valley buried by
   recent, often glacial deposits1161.

burst. 1. Periods of heavy rainfall[16]. 2. An
   explosive breaking of brittle rock material
   (e.g., rock burst in a deep mine tunnel).
                                             25

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caballing. The mixing of two water masses
  to produce a blend that sinks because of it
  is denser than its original components.
  This occurs when two water masses have
  the same density but different
  temperatures and salinities.

cable ladder.  A ladder used in vertical
  caving that is made of two parallel cables
  with metal rungs held in place on the
  cables with metal tubes crimped to the
  cables[13].

cable way. A cable stretched across a  river
  from which a cable car is suspended to
  allow for stream discharge
  measurements^161.

caisson.  A protective chamber for the
  excavation of water submerged
  unconsolidated sediments[16].

calanque. (French.) 1. Cove or small bay.
  2. A valley excavated in limestone or
  formed by collapse of the roof of a cave
  and subsequently submerged by a rise in
  sealevel[10].

calc-.  Prefix meaning limy; containing
  calcium carbonate[10].

calcarenite.  1. Limestone or dolomite
  composed of coral or shell sand or of
  grains derived from the disintegration and
  erosion of older limestones.  Size of
  particles ranges from 1/16 to 2
  millimeters^101. 2. A carbonate rock  that
  consists predominantly (>50%) of sand-
  sized calcite (or dolomite) particles.
  Many of the particles are the angular or
  degraded fragments of fossil shells[9].
calcareous.  1. Containing calcium
  carbonatetl0]. 2. Descriptive of a rock that
  contains calcium carbonate[9].

calcareous tufa.  See sinter.

calcification. Replacement of the original
  hard parts of an animal or plant by
  calcium carbonate[10].

calcilutite. 1. Clastic limestone or dolomite
  in which the grains have an average
  diameter of less than 1/16 millimeter;
  calcareous mudstone[10]. 2. A carbonate
  rock that consists predominantly (>50%)
  of silt and/or clay size calcite (or
  dolomite) particles191.

calcirudite.  A fragmental limestone in
  which the particles are generally larger
  than 2 millimeters1'01.

calcite.  1. The commoner, more stable,
  mineral form of calcium carbonate,
  CaCO3. It is the dominant component of
  all limestones and, due to its dissolution
  and reprecipitation by natural waters at
  normal  temperatures, it is also the
  dominant mineral of chemical cave
  deposits including stalactites and
  stalagmites. It is white or colorless when
  pure but may be stained, most commonly
  to yellows and browns, by included
  impurities such as iron oxides. Its
  uninterrupted growth in a pool may allow
  development of good crystals, shaped as
  elongate scalenohedral pyramids of
  trigonal habit.  Growth in stalactites and
  stalagmites is either in masses of fine
  parallel or radiating needles, or in a
  mosaic  of larger rhombic crystals, easily
  identified by their well developed
  cleavage surfaces. Calcite is also the
                                            26

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  dominant vein mineral in limestones191.  2.
  A mineral composed of calcium
  carbonate (CaCO3) like aragonite but
  differing in crystal form; the principal
  constituent of limestone and other
  speleothems[10].

calcite bubble. A hollow sphere formed by
  the deposition of calcite around a gas
  bubble; the interior is smooth, and the
  exterior consists of small jagged
  crystals™.

calcite flottante. (French.) See floe calcite.

calcite raft. A veneer of reprecipitated
  calcite forming a sheet over all or part of
  the surface of a static cave pool in
  conditions favoring the release of carbon
  dioxide[19].

calc-sinter. See sinter.

calcium carbonate. Naturally occurring
  compound with the  chemical formula
  CaCO3. It occurs commonly as the
  mineral calcite and less commonly as
 , aragonite, and is the major component of
  carbonate rocks including limestone and
  marble. It also forms the matrix or
  cement that holds together many
  sandstones and other sedimentary rocks[9].
  See also dolomite.

calcrete.  (South African.) See caliche.

calibration. The experimental evaluation of
  the scale readings of an instrument
  against an absolute standard[16].

caliche.  1. (Chilean and Peruvian.) A
  natural deposit of nitrates and other salts
  precipitated at the soil surface. 2.
  (Mexico and Southwestern United
  States.) Indurated calcium carbonate and
  other salts found in the soil at the surface
  in arid and semiarid regions, generally
  formed by evaporation of lime-bearing
  waters drawn to the surface by capillary
  action.  3. In some areas, refers to hardpan
  resulting from concentration of carbonate
  in the soil by downward leaching and
  reprecipitationP].  4. A deposit of
  precipitated minerals, mainly calcite or
  gypsum or both, formed in the soil or
  near-surface layers in arid and semi-arid
  zones at the horizon where ascendant
  capillary water evaporates and salts held
  in solution are deposited.  5. A similar
  deposit, formed by precipitation of salts
  leached from near-surface material and
  reprecipitated at shallow depths from
  downward moving waters[20]. Synonyms:
  (French.) croute; (German.) Kalkkruste,
  Ca-Horizont; (Greek.) apothema orikton
  aldton; (Italian.) caliche; (Spanish.)
  caliche; (Turkish.) kalici.  See also
  hardpan; havara; kafkalla; kankar;
  kunkar; nari; calcrete.

callow. (English.) Top or rubble bed of a
  quarry.

canal seepage loss. Water lost to the
  subsurface by seepage through the
  channel bottom or wallstl<5].

canale. (Italian.)  Long drowned valley on
  the Dalmatian coast. Some canali may be
  drowned poljes[10].

cano.  (Spanish.) Stream. See also stream.

canopy.  1. Overhanging fiowstone that
  projects from a cave wall. It may be a
  remnant of a once continuous false floor
                                            27

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  or a mass of flowstone that has built
  steadily outwards to create its own
  overhang[9]. 2. A compound cave
  formation consisting of flowstone
  hanging from a sloping wall projection
  and forming a fringe of shawls or
  stalactites on the outer edge[10].

canyon.  1. A steep-walled chasm, gorge, or
  ravine cut by running water. 2. A chasm
  that has been formed by a cave stream. 3.
  A valley formed by collapse of the roof of
  a long fairly straight cave; a karst
  valley1'01. Related to corridor.
  Synonyms: (French.) canyon, gorge,
  cdion; (German.) Schlucht,  Canyon;
  (Greek.) pharangi; (Italian.) forra, gola,
  orrido, canyon; (Russian.) kanjon;
  (Spanish.) canon;, garganta; (Turkish.)
  bogaz; (Yugoslavian.) klanac, sutjeska,
  soteska, vintgar.  See also bogaz; chasm;
  gorge; ravine.

canyon passage.  1. A tubular passage
   (cave) that is formed by underground
   streams following gently tilted bedding-
   plane partings or fractures and are eroding
   channels downward through the rock.
   Their ceiling heights are greater than their
   widths. They are similar to surface
   canyons, but they possess roofs and are
   generally the same distance apart at the
   top as they are at the bottom. In
   Mammoth Cave, most are narrow and
   winding and may achieve dimensions of
   50 feet wide by 100 feet high. If a canyon
   passage begins forming on an old tube
   passage, then a keyhole passage may
   result[151. 2. Also known as vadose
   canyons, these are cave passages, most
   commonly formed by continued floor
   entrenchment or incision, by a free
   flowing vadose stream. The passage
  width at any particular level is determined
  by the flow of the formative stream, the
  rate of its downcutting and the effects of
  any subsequent collapse.  Canyon height
  reflects the stream's downcutting history.
  It depends upon the vertical distance
  available for erosional descent to the local
  base level and the time that erosional
  downcutting has been active, as well as
  upon the more obvious but less important
  influences of flow rate and erosional
  capacity.  Vadose canyons commonly
  twist and meander sharply, while
  maintaining roughly parallel vertical
  sides. In contrast to some meanders in
  surface streams, underground meanders
  must generally be imprinted on a bedding
  plane before entrenchment of the canyon
  begins. Narrow canyon passages,
  commonly less than 1 m wide and more
  than 20 m high, are a particular feature of
  deep alpine caves.  Perhaps the largest
  canyon passage in the world is that in
  Skocjanske Jama, Slovenia, which is over
  100m high and 50 mwide[9]. See
  paragenetic cave.  See also keyhole
  passage; passage; tubular passage;
  vertical shafts.

capacity. The property to contain a certain
  volume or mass[16].

capacity, carrying.  The capacity of a
  watercourse to transport solids[16].

capacity curve.  A graphic presentation of
  the rate of discharge in a pipe !or conduit
  or through porous material[I6].

capacity, entrance. The property of a soil
  to let water infiltrate[I6].
                                             28

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capacity, field; field-carrying; capillary.
   Soil moisture retained by capillarity and
   not removable by gravity drainage1161.
   Synonym: specific retention.

capacity, ground-water.  1. The ability of
   soil or rock materials to hold water.  The
   yield of a pump, well, or reservoir.

capacity, hydraulic.  The ability of a
   current of water or wind to transport
   detritus, as shown by the amount
   measured at a point per unit of time.

capacity, infiltration. The maximum rate
   at which a soil can absorb precipitation
   for given conditions'151.

capacity, self-cleaning. The capacity of a
   river to clean its water from pollutants
   over a given length of water course[16].

capacity, specific.  The ratio of well
   discharge to corresponding discharge1161.

capacity, storage.  1. The ability of an
   aquifer to store water[16]. 2. The capacity
   of rivers to store water in their own
   channels[16].

capacity, total. The maximum rate of yield
   ofawell[16].

capacity, transmission. The property of a
   porous medium to conduct fluid[16].

capacity, well.  The rate at which  a well will
   yield water[16].

capillarity. The action by which a fluid,
   such as water, is drawn up (or depressed)
   in small interstices or tubes as a result of
   surface tension.
capillary action. The movement of water in
  the interstices of a porous medium due to
  capillary forces'221. Synonymous with
  capillarity, capillary flow, and capillary
  migration.

capillary attraction. The adhesive force
  between a liquid and a solid in capillarity.

capillary condensation. The formation of
  rings of pendular water around point
  contacts of grains, and, when the rings
  around adjacent contacts become large
  enough to touch.

capillary conductivity.  1. The property of
  an unsaturated porous medium to transmit
  liquid[22]. 2. Coefficient which expresses
  the extent to which an unsaturated
  permeable medium allows flow of water
  through its interstices, under a unit
   gradient of capillary potential'221.

capillary fringe. The lower subdivision of
   the unsaturated zone immediately  above
   the water table in which the interstices are
   filled with water under pressure less than
   that of the atmosphere, being continuous
   with the water below the water table but
   held above it by capillary forces'221.

capillary fringe zone. The zone above the
   free water elevation in which water is
   held by capillary action.

capillary head.  The potential, expressed in
   head of water, that causes the water to
   flow by capillary action'221.

 capillary interstice.  An interstice small
   enough to hold water by surface tension at
   an appreciable height above a free water
   surface, yet large enough to prevent
                                              29

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  molecular attraction from extending
  across the entire opening.

capillary migration.  See capillary action.

capillary movement. The rise of water in
  the subsoil above the water table by
  capillarity.

capillary percolation. See imbibition.

capillary potential.  The scalar quantity that
  represents the work required to move a
  unit mass of water from the soil to a
  chosen reference location and energy
  stated

capillary pressure.  The difference in
  pressure across the interface between two
  immiscible fluid phases jointly occupying
  the interstices of a porous medium caused
  by interfacial tension between the two
  phases1221.

capillary rise.  The height above a free
  water surface to which water will rise by
  capillary action[22]. Synonymous with
  height of capillary rise.

capillary stalagmite. Hollow stalagmite
  formed by saturated karst water pushed
  up through capillaries  and small cracks in
  a sinter crust covering permeable fluvial
  deposits on the floor of a cave; first
  reported from Cuba, where such
   stalagmites are composed of aragonite[101.

capillary tension. See moisture tension.

capillary water. 1. Water held in the soil
   above the phreatic surface by capillary
   forces^221. 2. Soil water above
  hydroscopic moisture and below the field
  capacity1221.

carabiner. An oval of steel or aluminum
  with a movable spring-loaded gate on one
  side.  A locking carabiner is one where
  the gate is threaded and has a ring that can
  be threaded over the gate opening to
  prevent it from opening[13].  Synonyms:
  karabiner; krab.

carbide, calcium carbide.  A compound
  (CaC2) of grayish color that reacts with
  water to produce acetylene gas and
  calcium hydroxide [Ca(OH)2][13].
  Commonly used by cavers and miners
  earlier in this century as a means of
  providing light in caves or mines. Some
  cavers still prefer carbide lights over
  electric lights.  See also carbide lamp.

carbide lamp. A carbide lamp, also known
  as a miners' carbide lamp or acetylene
  lamp was introduced into mine use at
  about 1897. It consists of two chambers,
  a water tank above and a removable
  carbide canister below with a connection
  valve to permit controlled seepage of
  water into the calcium carbide. The
  carbide and water react to generate
  calcium hydroxide [Ca(OH)2] and
  acetylene gas. The gas is passed through
  a filter into a tube and through a tiny
  burner-tip orifice designed for the
  optimum mixture of air and acetylene.
  Once ignited, it burns with a brilliant
  yellow-white flame produced by the
  incandescence of tiny carbon particles.  A
  reflector concentrates the light in a
  particular direction[13].       ;

carbonate.  1. A salt or ester of carbonic
   acid; a compound containing the radical
                                             30

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  CO3~2, such as calcium carbonate, CaCO3.
  2. A rock consisting mainly of carbonate
  minerals, such as limestone or
  dolomite1101.

carbonate-fluorapatite.  A cave mineral —
carbonate hardness.  Hardness of water
   due to presence of dissolved bicarbonates
   of calcium and magnesium which can be
   removed by boiling and hence the term
   'temporary hardness.'  Synonyms:
   (French.) durete temporaire; (German.)
   tempordre Hdrte, Carbonathdrte; (Greek.)
   parothiki sklipotis anthrakiki sklirotis;
   (Italian.) durezza temporanea; (Russian.)
   karbonatnaja zestkostj; (Spanish.) dureza
   temporal; (Turkish.) karbonat sertligi;
   (Yugoslavian.) turdooa, trdota.

carbonate-hydroxylapatite. A cave
   mineral — Ca5(PO4,CO3)3(OH)[ni.

carbonate rock. A rock that consists of one
   or more carbonate minerals.  Carbonate
   rock successions (or sequences) are those
   in which carbonate rock is dominant, but
   which also contain rocks of other
   lithology[9].

carbonic acid dissolution. Dissolution of
   calcium carbonate by carbon dioxide in
   aqueous solution, loosely termed
   carbonic acid, is the dominant reaction in
   karst processes, including speleogenesis.
   The reaction can be considered in several
   ways but it is most simply represented as:

     CaC03 + CO2 + H2O - Ca(HCO3)2

The reaction is reversible. The solution
containing the dissolved reaction product,
usually termed calcium bicarbonate, can lose
carbon dioxide to the atmosphere and
precipitate calcium carbonate. This process
is responsible for the development of
speleothems underground and tufa or
travertine at the surface[9].

carnivore. An animal that lives by eating
  the flesh of other animals[23]. See also
  herbivore; insectivore; omnivore.

cascading water. In reference to wells,
  ground water which trickles or pours
  down the casing or uncased borehole
  above the water level in the well through
  cracks or perforations'223.

casing. Permanent  liner of a well[161.

casing joint. Welded or threaded
  connection for tubular casing1161.

casing, surface. That part of a well casing
  that extends above land surface[16].

catch basin.  1. A reservoir or basin into
  which surface water may drain.  2. A
  basin to collect and retain material from a
   street gutter that would not readily pass
  through a sewer system.

catchment. (Great Britain.) 1. An area into
  which surface water may drain.  2. A
   depression that collects rainwater (e.g.,
   reservoir).

cation. An ion having a positive charge
   and, in electrolytes, characteristically
   moving towards  a negative electrode161.

cation exchange. Ion exchange process in
   which cations in solution are exchanged
   for other cations from an ion exchanger161.
                                             31

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cation exchange capacity.  The sum total of
   exchangeable cations that a porous
   medium can absorb. Expressed in moles
   of ion charge per kilogram of soil (or of
   other exchanges such as clay)[22].

causse.  (French.) A limestone plateau in the
   southeastern part of the central massif of
   France characterized by closed
   depressions, caves, and avens (jamas); a
   number of such plateaus in and around
   the basin of the river Tarn constitute Les
   Grandes Gausses.  This region was
   considered by Cvijic to exemplify karst
   development intermediate between
   holokarst and merokarst[10]. Synonym:
   (French.) causse; (German.) (Kalkstein
   Plateau), Causse; (Greek.) karstikon
   oropedion; (Italian.) altopiano carsico;
   (Russian.) izvestnjakovoje karstovoje
  plato; (Spanish.) altipla.no carstico;
   (Turkish.) kirecta§i diizlugii;
   (Yugoslavian.) krski plato, kraski plato.

cave. 1. 'A natural home in the ground,
   large enough for human entry' is probably
   the most useful definition. This covers
   the enormous variety of caves that do
   occur but eliminates the many artificial
   tunnels and galleries incorrectly named
   caves. The size criterion is arbitrary and
   subjective, but practical, as it eliminates
   narrow openings irrelevant to explorers
   but very significant hydrologically, that
   may be better referred to as proto-caves,
   sub-conduits or fissures.  A cave may be a
   single,  short length of accessible passage,
   or an extensive and complex network of
   tunnels as long as the hundreds of
   kilometers in the Flint Mammoth Cave
   System. Most caves are formed by
   dissolution in limestone but sandstone
   caves, lava caves, glacier caves and
  tectonic caves also occur. Marginal
  candidates for use of the name cave
  include riverbank undercuts and rock
  shelters of various origins. In some
  countries a cave is regarded as being a
  horizontal opening, as opposed to a
  pothole, which is a vertical opening. This
  usage is common in England but is not
  ubiquitous[9]. 2. A natural opening
  formed in the rocks below the surface of
  the ground large enough for a man to
  enter.  It may consist of a single
  connected opening or a series of small or
  large chambers connected by galleries[20].
  3. A similar artificial opening[10]. Related
  to cavern. Synonyms: (French.) grotte,
  caverne; (German.) Hohle, Grotte;
  (Greek.) spelean; (Italian.) caverna,
  grotta; (Russian.) pescera; (Spanish.)
  cueva; (Turkish.) magara; (Yugoslavian.)
  pecina. pec, pestera, spilja, zijjalka.jama.
  See also active cave; bedding cave; cave
  system; grotto; sea cave.

cave balloon.  See cave blister.

cave blister.  1. A small pimplelike cave
  formation, roughly oval in shape, gener-
  ally loose, and having a core of mud[IO].
  2. A partly or completely hollow
  hemispherical to nearly spherical
  speleothem, usually of gypsum; or
  hydromagnesite, attached to a cave wall.
  Synonym: cave balloon.

cave breakdown.  1. Enlargement of parts
  of a cave system by fall of rock masses
  from walls and ceiling. 2. Heaps of rock
  that have collapsed from the walls and
  ceiling of a cave, generally called cave
  breccia[10].  3. Synonym for the collapse of
  caves, or, in American usage, for the
  debris produced by collapse[18].
                                            32

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cave breathing. A resonance phenomenon
  in which air currents throb back and forth
  through constricted passages in a cave
  with periodicity of a few seconds to a few
  minutes. Synonyms: (French.) passage
  respirant; (German.) Grotte mil Resonanz;
  (Greek.) anapneousa ope; (Italian.) grotta
  a soffio alterno; (Spanish.) gruta
  resonante; (Turkish.) magara esintisi. See
  also blowing cave.

cave breccia.  Angular fragments of rock
  forming a fill in a cave, either cemented
  together by dripstone or in a matrix of
  cave earth1101. See also solution breccia.

cave bubble. A nonattached hollow sphere,
  usually of calcite, that has formed around
  a gas bubble on the surface of a cave
  pool.

cave coral. A rough, knobby growth of cal-
  cite resembling coral in shape, generally
  small; found on floor, walls, or ceiling of
  a cave[10].  Synonym: botryoid; coral for-
  mation; cave popcorn. See also
  knobstone.

cave cotton.  Thin flexible filaments of
   gypsum or epsomite projecting from a
   cave wall. Synonym: gypsum cotton.
   See also gypsum flower.

cave development. The inception of cave
   development in carbonate rocks begins if
   water can move through the bedrock and
   commence dissolution. The earliest
   water movement may be due to
   mechanisms (including ground-water
   pumping and ionic diffusion effects)
   unrelated to those dominating later
   development.  Similarly, inception may
   include physical  and chemical dissolution
(involving removal of carbonates and
mineral impurities by water and by strong
acids), as well as by the carbonic acid
dissolution that dominates later cave
growth. Initial water movement can be
along primary pores in the rock (in coarse
raffle limestones, oolites or chalk), along
relatively thin non-carbonate beds within
the succession, or along incipient or open
fissures (joints, faults and bedding
planes). These potential water routes are
initially very narrow and water movement
is severely restricted and laminar,
allowing only very slow dissolutional
growth (see gestation), until enlargement
beyond the turbulent threshold
(breakthrough) permits faster flow and
accelerated cave growth.  After
establishment of turbulent flow
conditions the effects of dissolution are
augmented by mechanical abrasion and
collapse, which expose new rock.  During
the early development stages a network of
narrow openings is formed.
Subsequently, geological factors guide the
preferential expansion of favorable
routes, which capture more of the local
flow and enlarge, at the expense of less
favorable openings, to form caves. The
less favorable fissures are relegated to a
subordinate role in transmitting
percolation water or, more rarely, in
carrying elements of overflow water
during floods. Also during the early
stages, all voids are water filled but as
permeability increases and true hydraulic
flow conditions are established, the upper
voids drain freely, forming a water table.
Almost all caves therefore originate under
phreatic conditions but the  overall
passage morphology is modified during
later growth into vadose or phreatic caves,
enlarged from the original phreatic
                                             33

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  imprint, above or below the water table.
  Ultimately, cave development evolves
  towards efficient drainage close to the
  water table.  Passage enlargement then
  becomes regressive as collapse increases.
  The stage of a cavernous karst collapsing
  extensively is relatively rarely achieved,
  being overtaken at high latitudes  and high
  altitudes by surface lowering, but such
  collapse can contribute to the chaotic land
  forms of tropical karst[9].

cave earth, cave fill. Insoluble deposits of
  clay, silt, sand, or gravel flooring or fill-
  ing a cave passage. In a more restricted
  sense, cave earth includes only the finer
  fractions: clay, silt, and fine sand
  deposits1101.  Synonym: cave soil.

cave ecology.  The study of the interaction
  between cave organisms  and their
  environment, e.g. energy input from
  surface, climatic influences1251.

cave fill. Transported materials such as silt,
  clay, sand and gravel which cover the
  bedrock floor or partially or wholly block
  some part of a cave[2S1.

cave flower. An elongate curved deposit of
  gypsum or epsomite on a cave wall  in
  which growth occurs at the attached
   end[10]. Synonyms: gypsum flower;
   oulopholite. See also anthodite; cave
   cotton.

cave formations.  1. Secondary mineral de-
   posits formed by the accumulation, drip-
   ping, or flowing of water in a cave[10]. 2.
   Unsatisfactory term used to include all
   varieties of calcite, gypsum and  other,
   rarer, mineral cave deposits; therefore a
   synonym for the equally unwieldly
  speleothem or the colloquial term
  'stall'[91. See also sinter; speleothem.

cave group. A number of caves or cave
  systems, not interconnected but geo-
  graphically associated in some, relief
  feature or particular geological outcrop[10].
  See also cave series.

cave guano. Accumulations of dung in
  caves, generally from bats; in some places
  partially mineralized1101.

cave ice. Ice formed in a cave by natural
  freezing of water.  Loosely but incorrectly
  applied to calcium carbonate dripstone
  and flowstone[10].

cave-in. 1. The collapse of the ceiling or
  side walls of a cave or of the land surface
  into a subterranean passage as a result of
  undermining or of pressure from above[10].
  2. The partial or complete collapse of
  earth material into a large underground
  opening, such as an excavation or a mine.
   3. The sudden slumping of wall material
  into a pit. 4. A place where material has
   collapsed or fallen in or down.

cave-in lake.  A shallow body of water
   whose basin is produced by collapse of
   the ground following thawing of ground
   ice in regions underlain by permafrost.
   Synonym: thermokarst lake.

cave lake. Any underground lake. The
   water can be in a partially drained
   phreatic cave, and may then be the
   entrance to a sump, or it can be open over
   its entire surface,  hi vadose caves lakes
   are most commonly formed by ponding
   behind banks of sediment or, in rarer
   cases, behind very large gour barriers[9].
                                             34

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cave marble. Banded deposit of calcite or
  aragonite capable of taking a high
  polish[10]. See also fiowstone; onyx.
  marble.

cave of debouchure.  Outflow cave.

cave onyx. See onyx marble.

cave pearl.  1. Carbonate concretion,
  usually of calcite, that is spherical or
  irregular in shape, with an internal
  structure of concentric banding round a
  central grain.  Pearls form in pools of
  saturated water disturbed by dripping
  water, so that they are commonly found
  beneath high avens. Individual pearls
  may be 1mm or many centimeters in
  diameter. Movement of the larger ones
  may become impossible and they can then
  become cemented to the pool floor.
   Some caves contain spectacular displays
   of cave pearls; in Jackson's Bay Cave,
   Jamaica, they cover large areas of passage
   floor behind low gour barriers[9]. 2. Small
   concretion of calcite or aragonite formed
   by concentric precipitation around a
   nucleus1101.  Synonyms: pisolite; pisolith;
   (French.) perle des cavernes; (German.)
   Hohlenperlen; (Greek.) speleomargarites;
   (Italian.)perle di grotta; (Russian.)
  pescernij zemcug; (Spanish.) perla de
   caverna; (Turkish.) magara incisi;
   (Yugoslavian.) pecinski biseri, jamski
   biseri.

 cave pisolite. See cave pearl.

 cave popcorn. See cave coral.

 cave postule. A white, hemispherical wall
   and roof deposit of calcite[25].
cave raft. A thin mineral film, usually of
  calcite, floating on a cave pool.

Cave Research Foundation (CRF.) An
  organization of cavers united primarily
  for scientific exploration and study of
  cavestl3].

cave spring. See spring, cave.

caver.  (American.) 1. A slang term for one
  who engages in the hobby of cave
  exploration, or caving[9'21]. 2. A person
  who explores caves in a safe manner
  while showing respect for the cave (all
  aspects of the cave), other cavers, and  the
  land above the cave[I3].  Synonym:
  spelunker; (British.) potholer. See also
  speleologist.

cavern.  1. Underground opening in soluble
  rock similar to a cave.  When used as a
  noun, it refers to large openings, but when
  used as an adjective it tends to refer to
  rock texture and so to small openings.
  However, in some countries (e.g., Russia)
   cavern refers to small openings in a
  rock[20]. 2. A synonym of cave with the
   implication of large size.  3. A system or
   series of caves or cave chambers. 4. A
   cave, often used poetically or to connote
   larger-than-average size[10]. Synonyms:
   (French.) caverne; (German.) Hohle,
   Kaverne; (Greek.) spelean; (Italian.)
   caverna, grotta; (Russian.) kaverna;
   (Spanish.) caverna, cueva; (Turkish.)
   kovuk; (Yugoslavian.) kaverna. See also
   cave.

 cavern breakdown. The process of cave
   enlargement which depends upon the
   mechanical failure and eventual collapse
                                             35

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  of sections of the cavern walls and
  ceiling[22].

cavern flow. Movement, often turbulent, of
  ground-water flow through caves, coarse
  sorted gravel, or large open conduits,
  either by gravity or under pressure.

cavernicole.  An animal which normally
  lives in caves for the whole or part of its
  life cycle1253.

cavernous. Adjective used to describe a
  rock texture in which the rock contains
  openings generally of a small size[20].
  Synonyms: (French.) caverneux;
  (German.) kavernos; (Greek.) speleothes;
  (Italian.) con grotte; (Russian.)
  kavernoznij', (Spanish.) cavernoso;
  (Turkish.) kovuklu; (Yugoslavian.)
  kavernozan. See also cavern.

cavernous karren.  Pitted, rubbly limestone
  most commonly found in relatively recent
  and Tertiary limestones of the humid
  tropics131. See also covered karren;
  karren.

cavernous permeability.  See conduit
  permeability.

cavernous rock. Any rock that has many
  cavities, cells, or large interstices (e.g., a
  cliff face pitted with shallow holes
  resulting from cavernous weathering).

cavernous weathering. Chemical and
  mechanical weathering on a cliff face, in
  which grains and flakes of rock are
  loosened so as to enlarge hollows and
  recesses.
cavern porosity.  A pore system having
  large, cavernous openings.  The lower
  size limit, for field analysis, is practically
  set at approximately the smallest opening
  that an adult person may enter.

cavern system. See cave system.

cave series. A group of caves of similar
  morphology in a particular district[10]. See
  also cave group.

cave shield. A semicircular plate of
  reprecipitated calcite located beneath
  joints in a cavern ceiling and believed to
  be formed by the seepage of hydrostatic
  water along the joint.  Two shields form
  beneath one joint, descending from each
  side of the opening[22].

cave soil.  See cave earth.

cave spring.  See spring, cave.

cave system. 1. An underground network of
  passages, chambers, or other cavities. 2.
  The caves in a given area related to each
  other hydrologically, whether continuous
  or discontinuous from a single opening[10].
  Synonyms: (French.) reseau souterrain;
  (German.) Hohlensystem; (Greek.)
  speleothes systema, thiction; (Italian.)
  sistema carsico sotterraneo; (Russian.)
  sistema podzemnih pescer;  (Spanish.)
  sistema de cavidades; (Turkish.) magara
  sistemi, serisi; (Yugoslavian.) pecinski
  (spiljski) sistem, amski sis tern. \ See also
  cave; cave group; cave series; cavern.

caving.  The sport of exploring caves.
  Synonyms: (British.) potholing;
  spelunking. 2. A method of mining in
  which the ore is allowed to cave or fall[10].
                                             36

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cavings. Rock fragments that fall from the
  walls of a borehole and contaminate the  .
  well cuttings or block the hole. These
  fragments must be removed by drilling or
  circulation of drilling fluids before the
  borehole can be deepened.

cavitation. 1. The collapse of bubbles in a
  fluid, caused by static pressure being less
  than the fluid vapor pressure.  2. A
  phenomena of cavity formation, or
  formation and collapse, especially in
  regard to pumps, when the absolute
  pressure within the water reaches  vapor
  pressure causing the formation of vapor
  pockets[6].

cavity.  A solutional hollow in a limestone
  cave.

cavity dweller. A coelobitic organism.

ceiling block. Roughly cubical joint-
  bounded large block, which has fallen
  from the ceiling of a cave[IO]. See also
  cave breakdown; ceiling slab.

ceiling cavity.  Solutional concavity in the
  ceiling of a cave. The orientation is
  determined by joints or a bedding
  plane'10!.

ceiling channel.  Sinuous channel
  developed in the ceiling of a cave,
  presumably during the phreatic phase of
  cave development^01.

ceiling meander. A winding upside-down
  channel in a cave ceiling1101.

ceiling pocket. See pocket.
ceiling slab, roof slab. A thin but extensive
  piece of rock that has fallen from the
  ceiling of a cave in roughly horizontal
  limestone1101. See also cave breakdown;
  ceiling block.

ceiling tube. A half tube remaining in the
  ceiling of a cave[101.

celestite. A cave mineral —• SrSO4[1I].

cement.  A microscopic textured nonskeletal
  void-filling material precipitated on an
  intragranular or intrasedimentary free
  surface that holds the material together1201.
  Synonyms: (French.) ciment; (German.)
  Zement; (Greek.) tsimento; (Italian.)
  cemento; (Spanish.) cemento; (Turkish.)
  gimento; (Yugoslavian.) vezivo cement.

cementation. The process of binding
  granular material together by deposition
  of cementing material at contact points of
  grains[16].

cement grout.  Cement slurry of pumpable
  consistency1161.

cement slurry. Liquid cement
  suspension^61.

cementing.  See grouting.

cenote. (Spanish,  after Mayan tzonet or
  dzonot.} 1. Steep-walled natural well that
  extends below the water table; generally
  caused by collapse of a cave roof.  Term
  used only for features in Yucatan[10]. 2.
  Steep or vertical sided collapse doline
  floored by a lake whose surface is at the
  regional water table. The term originates
  from the many cenotes in the low karst
  plateau of Mexico's Yucatan, but has
                                             37

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  been applied to flooded dolines in Florida
  and elsewhere. Probably the most famous
  cenote is the sacred well of Chichen Itza,
  Yucatan; it has vertical sides and is 60m
  in diameter, 30m deep and half full of
  water191. Synonyms: (French.) cenote;
  (German.) cenote; (Greek.) voulismeno
  speleven.  See also jama; natural well.

centrifuge moisture equivalent.  See
  moisture equivalent.

cerussite. A cave mineral — PbCO3[11].

chain gage.  Water level measuring
  device1161.

chalk. 1. Used as a proper noun chalk
  describes a rock unit of Cretaceous age,
  that consists predominately of relatively
  soft, white, porous limestone with beds of
  marl and bands or nodules of flint.  The
  term is used without its initial capital to
  describe any rock with similar appearance
  and properties. Generally chalk has a
  relatively high primary permeability and
  so rarely develops caves of explorable
  size, though conduit-water flow does
  occur. Some harder chalks in northern
  France and south-eastern England hold
  explorable active and relict caves, which
  extend for many hundreds of meters[9].  2.
  Soft poorly indurated limestone, generally
  light in color; commonly composed of the
  tests of floating microorganisms in a
  matrix of very finely crystalline calcite[10].

chalcanthite.  A cave mineral —
  CuSO4-5H20[111.

chamber. (American.) 1. An enlargement
  in a cave passage or system, commonly
  formed at a junction of passages, or
  locally in a single passage, where erosion
  has been enhanced by collapse [exposing
  more rock to dissolution.  Maximum
  chamber size is controlled by the strength
  and shape of the limestone ceiling. The
  largest chamber currently known,
  Sarawak Chamber in Lubang Nasib
  Bagus, at Mulu, Sarawak, is over 700m
  long, up to 400m wide and nowhere less
  than 70m high. It has formed where a
  large stream eroded sideways as it cut
  obliquely across the included bedding in
  unusually massive limestone. It is
  doubtful whether a much larger chamber
  could exist without collapse of its roof191.
  2. The largest order of cavity in a cave or
  cave system; it has considerable length
  and breadth but not necessarily great
  height.  3. (British.) A room in a cave[10].
  Synonyms: (French.) salle; (german.)
  Halle, Kammer, Dom; (Greek.) ypoyios
  aethousa; (Italian.) sala; (Russian.);za/;
  (Spanish.) sala, salon; (Turkish.) oda;
  (Yugoslavian.) dvorana.  See also room;
  passage.

chandelier.  Large variety of gypsum
  flower, with branching crystal structure
  that may hang many meters from a cave
  ceiling. Very rare, except in Lechuguilla
  Cave of New Mexico[9].

channel. Natural or artificial watercourse
  bounded by banks[16].       |

channel characteristics.  Hydraulic
  properties of stream channel1161.

chasm. 1. A deep, fairly narrow breach in
  the earth's surface; an abyss; a gorge; a
  deep canyon.  2. A deep, wide, elongated
  gap in the floor of a cave[10].  Related to
  canyon, corridor. Synonyms: (French.)
                                            38

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  gouffre, fracture ouverte; (German.) Kluft;
  (Greek.) chasma; (Italian.) fattura beante,
  canyon; (Spanish.) canon, taso; (Turkish.)
  derm yannti; (Yugoslavian.) provalija.
  See also ravine.

chemical carbonate rock. Carbonate rock
  form by the precipitation of mineral
  matter in situ by chemical or biological
  processes.

chemical deposit. A sediment precipitated
  out of solution by chemical action[16].

chemical erosion. Processes partially
  synonymous with chemical dissolution,
  but including any other form of rock
  breakdown accelerated by chemical
  changes of the constituent minerals191.

chemical equivalent.  The expression of
  water characteristics such as hardness or
  alkalinity resulting from several ions in
  solution in terms of only one equivalent
  concentration116].

chemical mobility.  The tendency of an
  element to move in a given
  hydrogeochemical environment1'61.

chemical oxygen demand (COD.) The
  measure of readily available oxidizable
  material contained in a water sample1163.

chert, chert nodule. 1. Black, brown or
  grey rock, consisting of very fine-grained
  silica, that occurs as horizons of nodules
  and discontinuous bands, generally less
  than 200mm thick, within many
  limestones. It is very hard and almost
  insoluble in water, so commonly it
  projects from cave walls where it forms
  passage or shaft ledges and waterfall
   lips[9]. 2. Light-cream or gray to black
   rock .composed of silica, found occurring
   as nodules or layers in limestone, or as a
   replacement of limestone[10].

Chezy equation.  An equation used to
   compute the velocity of uniform flow in
   an open channel: mean velocity of flow
   (V) equals the Chezy coefficient © times
   the square root of the product of hydraulic
   radius in feet (R) times the slope of the
   channel[1].  See also Froude number;
   Manning equation; Reynolds number.

chimney. 1. Nearly circular shaft rising
   upwards from the ceiling of a cave
   towards the surface of the ground; if it
   does not reach the surface it is termed a
   blind chimney. If the chimney is formed
   mainly by solution, it is related to a dome-
   pit; if formed mainly by collapse of the
   roof along bedding planes, it is related to
   cenote[20]. 2. A narrow vertical shaft in
   the roof of a cave, generally smaller than
   an aven; a dome pit[10].  Synonyms:
   (French.) cheminee (aven); (German.)
   Schlot, Kamin;  (Greek.) kapnothochos;
   (Italian.) camino; (Russian.) truba;
   (Spanish.) chimenea; (Turkish.) baca;
   (Yugoslavian.)  dimnjak.

chimneying. Ascending or descending by
   means of opposed body and/or limb
   pressures against two facing walls[25].

chlorophyll. A group of pigments
   producing the green color of plants;
   essential to photosynthesis[23].

chock. A block of metal for use as a
   chockstone[25].
                                            39

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chockstone. A rock wedged between the
  walls of a cave passage[10].

choke. 1. A blockage of inwashed mud,
  sand or boulders in a cave passage. Most
  boulder chockes are formed by collapse
  of a passage roof and may have an open
  chamber or shaft above them; others are
  formed by collapse and inwashed debris
  where a large old passage is cut by a
  hillside. A passable route through a
  choke may be opened by excavation, and
  thereby lead to discovery of new passage
  — as was done so successfully in Ogof
  Agen Allwedd[9]. 2. Rock debris or cave
  fill completely blocking a passage[10].

C-horizon. Zone of weathered parent
  material in a soil profile[16].

chute. An inclined channel or trough in a
cidnaga. (Spanish.) Wetland. See also
  wetland.

cimolite. A cave mineral —
  Al4(Si02)9(OH)I2tn].

cistern. A small water reservoir used to
  collect surface and rain water[16].

classical karst.  Originally the region called
  Kras in Slovenia, which gave its name to
  the karst landscape.  Used in this sense
  about 95% of the classical karst lies in
  Slovenia, with the remaining 5%
  extending to Italy. A slightly different
  area was covered by descriptions of early
  investigations or karst phenomena, when
  the name classical karst was applied to a
  region between Ljubljana, Gorizia and
  Rijeka, mainly in Slovenia with some
  parts in Italy and Croatia[9].

clastic. Pertaining to a rock or sediment
  composed principally of broken
  fragments that are derived from pre-
  existing rocks or minerals and that have
  been transported some distance from their
  places of origin[6].

clastic carbonate rock.  Carbonate rock that
  is made up of carbonate grains (e.g.,
  shells, shell fragments, oolites).

clastic rock; detrital rock. A sedimentary
  rock derived from fragmentated other
  preexisting rock or organic structures^61.

clastokarst. Karst phenomena in clastic
  rocks composed of detrital carbonate
  material[20].  Synonyms: (French.)
  clastokarst; (German.) Klastokarst?;
  (Greek.) clastokarst; (Italian.) carsismo
  clastico; (Russian.) klastokarst; (Spanish.)
  clastokarst; (Turkish.) klastik karst;
  (Yugoslavian.) klastokfs klastokras,
  klastokarst.

claustrophobia. An irrational fear of being
  in a closed space[25].

clay.  1. A rock or mineral fragment or a
  detrital particle of any composition
  smaller than a very fine silt grain, having
  a diameter less than 1/256 mm (4
  microns, or 0.00016 in., or 8 phi units.)
  This size is  approximately the upper limit
  of size of particle that can show colloidal
  properties.  2. A loose, earthy, extremely
  fine-grained natural sediment or soft rock
  composed primarily of clay-size or
  colloidal particles and characterized by a
  considerable content of clay minerals and
                                            40

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  subordinate amounts of finely divided
  quartz, decomposed feldspar, carbonates,
  ferruginous matter, and other impurities.
  It forms a plastic, moldable mass when
  finely ground and mixed with water, but
  retains its shape on drying, and becomes
  firm, rocklike, and permanently hard on
  heating or firing. 3. A term that is
  commonly applied to any soft, adhesive,
  fine-grained deposit (such as loam or
  siliceous silt) and to earthy material,
  particularly when wet (such as mud). 4.
  A term used by the International Society
  of Soil Science for a rock or mineral
  particle in the soil, having a diameter less
  than 0.002 mm (2 microns).

clay ball, clayball. A chunk of clay
  released by erosion of a clayey bank and
  rounded by wave action.

clay boil. A mud circle that suggests a
  welling-up or heaving of the central core.

clay colloid.  1. A clay particle having a
  diameter less than 1 micron (0.001 mm.)
  2. A colloidal substance consisting of
  clay-size particles.

clay fill. Dry or wet clay that fills a cave
  passage[10].

clay filling. Time interval between end of
   phreatic solution of a cave and beginning
   or deposition of flowstone[10].

clayey sand.  1. An unconsolidated
   sediment containing 50-90% sand and
   having a ratio of silt or clay less than 1:2.
   2. An unconsolidated sand containing
   40-75% sand, 12.5-50% clay, and 0-20%
   silt.
clayey silt. 1. An unconsolidated sediment
  containing 40-75% silt, 12.5-50% clay,
  and 0-20% sand. 2. An unconsolidated
  sediment containing more particles of silt
  size than of clay size, more than 10%
  clay, and less than 10% of all other
  coarser sizes.

clay loam. A soil containing 27-40% clay,
  20-45% sand, and the remainder silt.

clay marl. 1. A whitish, smooth, chalky
  clay. 2. A marl in which clay
  predominates.

clay mineral. One of a complex and loosely
   defined group of finely crystalline,
   metacolloidal,  or amorphous hydrous
   silicates, essentially of aluminum.

claypan.  A dense, heavy, relatively
   impervious subsurface soil layer that
   owes its hardness to a relatively higher
   clay content than that of the overlying
   material from which it is separated by a
   sharply defined boundary.

 clay parting.  1.  Clayey material between a
   vein and its wall. 2. A seam of hardened
   carbonaceous clay between or in beds of
   coal, or a  thin layer of clay between
   relatively thick beds of some other rock
   (e.g., sandstone).

 clay plug. Fine flood deposits in a cut off
   river meander[16].

 clean sand.  Sand with little or no clay
   content1161.

 cleavage. The tendency to cleave or split
   along definite parallel planes, which may
   be highly inclined to the bedding. It is a
                                             41

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   secondary structure and is ordinarily
   accompanied by at least some
   recrystallinization of the rock.

climate. The average weather conditions of
   an area, including temperature, rainfall,
   humidity, wind, and hours of sunlight,
   based on records kept for many years[23].

climatic factor. A factor influencing
   hydrologic parameters due to the local
   climatetl6].

clinometer. An instrument for measuring
   vertical angles or angles of dip[25].

clint. (British.) 1. Flat or sloping bare
   limestone outcrops (limestone
   pavements) weathered into straight-sided
   or furrowed blocks and ridges of
   limestone which are separated by deep
   clefts or solutionally widened joints
   (grikes) that often crisscross[20]. 2. Slabs
   of limestone, parallel to the bedding,
   forming a pavement. Widened joints, or
   grikes, isolate individual clints[10].
   Synonym: (French.) lapiaz; (German.)
   Flachkarren, Karrenfeld; (Greek.) pethion
   amaxotrochion thactyloglyphon; (Italian.)
   campo carreggiato; (Russian.) karrovoe
   pole; (Spanish.) campo de lapiaz, lenar;
   (Turkish.) purtiiklu, ohiklu;
   (Yugoslavian.) skrapari, skraplje.  See
   also grikes; karrenfeld; lapies; limestone
   pavement.

clog, to. The action of blocking fluid flow
   paths, especially around a well bore[16].

clogger. A type of ascender without a
   handle; used with a karabiner to keep it
   securely on the rope[25].
closed depression, closed basin.  1. Any
  karst hollow with internal drainage,
  including dolines, uvalas, poljes, cockpits
  and all varieties of blind karst valleys, of
  both small and large scales[9]. 2. A
  general term for any enclosed topographic
  basin having no external drainage,
  regardless of origin or size[10].

closed karst. A karst terrane that is covered
  by sediments.  Synonyms: (Russian.)
  skrytyl karst or zakrytyl karst. See also
  buried karst; interstratal karst; mantled
  karst.

closed traverse.  A traverse which begins
  and ends at survey points with known
  co-ordinates and orientation or at the
  same point[25].

cloud. Large masses of coralloid or
  botryoidal calcite, deposited under water,
  with each mass reaching 200-800mm in
  diameter. Famous examples hang above
  the Lake of the Clouds in Carlsbad
  Cavens, New Mexico[9].

clusterite.  Seebotryoid.

coarse. Composed of or constituting
  relatively large particles.

coarse sand. 1. A geologic term for a sand
  particle having a diameter in the range of
  0.5-1 mm (500-1000 microns, or 1 to
  zero phi units.) 2. An engineering term
  for a sand particle having a diameter in
  the range of 2  mm.  3. A soil term used in
  the U.S. for a sand particle having a
  diameter in the range of 0.5—1 mm (the
  diameter range recognized by the
  International Society of Soil Science is
  0.2-2 mm).
                                             42

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coarse silt. A geologic term for a silt
  particle having a diameter in the range of
   1/32 to 1/16 mm (31-62 microns, or 5 to
  4 phi units).

cockpit. (Jamaican.) 1. Any closed
  depression having steep sides. 2. A
  star-shaped depression having a conical
  or a lightly concave floor. The
  surrounding hill slopes are steep and
  convex. Cockpits are the common type
   of closed depressions in a kegelkarst[l°\

cockpit karst. (Jamaican.) 1. Term
   describing an area containing numerous
   scattered, yet closely spaced dolines;
   generally a tropical karst land form. The
   corresponding Yugoslav term may more
   accurately be translated as 'pock-marked'
   karst. 2. Tropical karst topography
   containing many closed depressions
   surrounded by steep-sided conical hills.
   Divided by French and German
   geographers into several types depending
   on shape of hills[10]. Synonyms: (French.)
   karst cockpit; (German.) Turmkarst,
   Kegelkarst; (Greek.) dolinovrithes karst;
   (Italian.) campo carsico a doline;
   (Spanish.) karst esponja; (Turkish.)
   dildenli karst; (Yugoslavian) boginjavi
   krs, kozavi kras. See also cone karst;
   Halbkugelkarst; Kegelkarst;
   Spitzkegelkarst; tower karst.

 coefficient of compressibility.
   Compressibility is the aptitude of the soil
   to be deformed. It is expressed by means
   of a coefficient which is the ratio between
   a void ratio decrease from e0 to e and an
   increase in effective stress.  The value ^
   = e0-eAp represents the coefficient of
   compressibility for the range p0 to p0 + p.
  Units are usually cm2/kgI21].  See also
  coefficient of volume compressibility.

coefficient of permeability. An obsolete
  term that has been replaced by the term
  hydraulic conductivity^.

coefficient of storage. See storage
coefficient.

coefficient of transmissivity; coefficient of
  transmissibility. An obsolete term
  replaced by the term transmissivity.

coefficient of volume compressibility. The
  compression of a clay (aquitard) per unit
  thickness, due to a unit increase of
  effective stress, in the load range
  exceeding preconsolidation stress. It is
  expressed by the equation

                       a,.
   in which e0 is the initial void ratio. Units
   are usually cm2/kg[21].  See also coefficient
   of compressibility.

cohesion.  Shear resistance at zero normal
   stress.  An equivalent term in rock
   mechanics is intrinsic shear strength.

coliform organism. A microorganism, the
   concentration of which is used as an
   indication of the degree of biological
   pollution of water[16].

collapse breccia.  A mass of rock composed
   of angular to rounded fragments of
   limestone or dolomite that has formed as
   the result of the collapse of the roof of a
   cave, of an underlying cave, or of an
                                             43

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  overhanging ledge[10]. See also solution
  breccia.

collapse chamber. An underground
  chamber containing notable quantities of
  collapsed material.  The term is
  commonly abused in describing the origin
  of cave chambers floored by collapse
  debris. Though wall and roof collapse are
  common modifying processes in larger
  chambers, it is important to remember
  that such collapse cannot form a chamber,
  as it can only take place into a pre-
  existing cavity191.

collapse sink; collapse sinkhole.  1. A
  variety of closed depression that forms by
  collapse of the rock above an existing
  cave passage or chamber[9]. 2. A closed
  depression formed by the collapse of the
  roofofacave[10]. See also doline.

collapse of caves.  Collapse and breakdown
  of cave walls and ceilings are continuing
  aspects of cave development  and
  modification.  Massive unfractured
  limestone can easily span a void of over
  100m, but thinly bedded, closely jointed,
  faulted or poorly lithified limestone may
  collapse into very small passages.
  Collapse is a significant component of
  cave erosion.  As well as simple falls of
  unsupported rock forming connections
  between passages, the collapse process
  exposes more rock surface area for
  potential dissolution.  As rates of collapse
  are measured on a geological time  scale
  collapse in natural caves offers a
  negligible threat to explorers, in
  comparison to the dangers of roof
  collapse in mines[91.
collector well. A central well with
  horizontal sections of screened collector
  pipe arranged radially to increase yield£16].

colloid. Extremely small solid particles,
  0.0001 to 1 micron in size, which will not
  settle out of solution.  It is intermediate
  between a true dissolved particle and a
  suspended solid which will settle out of
  solution[6].

column. 1. A subsurface dripstone
  formation produced by the union of a
  stalactite and a stalagmite in acave[20\ 2.
  A flowstone formation, generally
  cylindrical, formed by the union of a
  stalactite and stalagmite[10]. Not to be
  confused with pillar. Synonyms:
  (French.) colonne, pillier stalamitique;
  (German.) Tropfstein-Sdule; (Greek.)
  stalaktitike stele; (Italian.) colonna
  (stalagmitica o stalattitica) (Russian.)
  kolonna; (Spanish.) columna; (Turkish.)
  siltun; (Yugoslavian.) stup, steber, stolpic
  See also pillar.

comminution.  The reduction of a substance
  to a fine powder; pulverization;
  trituration.

community. All the plants and animals that
  live in a particular habitat and^are bound
  together by food chains and other
  interrelations1231.

compaction. A decrease in the volume of a
  mass of sediments from any cause. In
  general, compaction may be regarded as
  the decrease in the thickness of
  sediments, as a result of an increase in
  vertical compressive stress, and is
  synonymous with 'one-dimensional
  consolidation,' as used by engineers. The
                                            44

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  term compaction is applied both to the
  process and to the measured change in
  thickness.  In thick fine-grained beds,
  compaction is a delayed process
  involving the slow escape of pore water
  and the gradual transfer of stress from
  neutral to effective. Until sufficient time
  has passed for excess pore pressure to
  decrease to zero, measured values of
  compaction are transient1211.  See also
  compaction, residual; compaction,
  specific.

compaction, residual.  Compaction that
  would occur ultimately if a given increase
  in applied stress were maintained until
  steady-state pore pressures were achieved,
  but had not occurred as of a specified
  time because excess pore pressures still
  existed in beds of low diffusivity in the
  compacting system.  It can also be
  regarded as the difference between (1) the
  amount of compaction that will occur
  ultimately for a given increase in applied
  stress, and (2) that which has occurred at
  a specified time[21]. See also compaction;
  compaction, specific.

compaction, specific. The decrease in
  thickness of deposits, per unit of increase
  in applied stress, during a specific period
  of time[21]. See also compaction;
  compaction, residual.

compass. An instrument with a magnetic
needle which is free to point to magnetic
north. For survey the needle is either
attached to a graduated card or can be
read against a graduated circle to measure
the angle in degrees from the north
clockwise[25].
competition. The struggle between
  individuals or groups of living things for
  common necessities, such as food or
  living spacet23].

complete well penetration, fully
  penetrating.  1. The property of a well
  that penetrates an aquifer completely from
  the upper confining bed or water table to
  the lower confining bed[16]. 2.  A well that
  is completed over the whole thickness of
  the aquifer to allow radial production over
  its entire completed length[16].

compressibility.  The relative change in
  volume with pressure of water or aquifer
  matrix[16].

compressive stress.  Normal stress tending
  to shorten the body in the direction in
  which it acts.

compromise boundary.  1. A plane
  interface between two crystals which
  evolved by mutual interference of their
  respective growing faces. This interface
  is a face of neither crystal. 2. A
  microscopic texturet20].

concentration gradient.  The change in
   solute concentration per unit distance in
   solute.  Concentration gradients cause
  Fickian diffusion (spreading) of solutes
   from regions of highest to regions of
   lowest concentrations,  hi slowing
   moving ground water, this is the
   dominant mixing process1221.

concretion. The localized deposition of
   mineral matter going out of solution in
   sediments or tuffs, usually nodular or
   irregular in shape[16].
                                             45

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condensation. The transition from vapor to
   liquid state1163.

condensation nucleus. A small solid
   particle around which condensation
   occurs[16].

condensation water.  Atmospheric moisture
   deposited inside caves when the surface
   temperature of the exposed rock falls
   below the dew point of circulating air[19].

conduit; karst conduit. Relatively large
   dissolutional voids, including enlarged
   fissures and tubular tunnels; in some
   usage the term is restricted to voids that
   are water-filled. Conduits may include all
   voids greater than 10mm in diameter, but
   another classification scheme places them
   between arbitrary limits of 100mm to
   10m. Whichever value is accepted in a
   particular context, smaller voids are
   commonly termed sub-conduits[9].
   Synonyms: (French.) conduiteforcee;
   (German.) Druckleitung (Leitung);
   (Greek.) siphon; (Italian.) condotta
   forzata; (Spanish.) conducto saturado;
   (Turkish.) yemltisu yolu,  mecra. See also
   pressure flow tube; stream tube; siphon.

 conduit flow; karst conduit flow.
   Underground water flow within conduits.
   Conduit flow is generally turbulent, but
   can also be laminar191.

 conduit permeability.  Sometimes referred
   to as cavernous permeability, this is a
   measure of the efficiency with which a
   particular aquifer transmits water through
   conduits (see permeability)191.

 conduit porosity. That part of the porosity
   within an aquifer (usually a karst aquifer)
  that is a function of the presence of
  conduits [9].

cone of depression. A depression of the
  potentiometric surface in the shape of an
  inverted cone that develops around a well
  that is being pumped.  It defines the area
  of influence161.  Synonym: cone of
  pressure relief (applied to artesian
  aquifers only).

cone of impression. A rise of the
  potentiometric surface in the shape of a
  cone that develops around an injection
  well[22].

cone karst. 1. A karst landscape dominated
  by low conical (or hemispherical) hills
  that forms only in wet tropical climates.
  The type example is Gunung Sewu in
  Java. Individual  hills are remarkably
  uniform, each some few hundred meters
  in diameter and around 50m high.
  Between them lie broken valleys, dolines
  or cockpits, draining into sinkholes.
  Erosion that seems to be initiated in
  valley systems develops in such a way
  that the valleys break up into dolines, but
  the mechanisms leading to uniform
   shaping of the hills are not fully
   understood.  The widespread cone karst in
   China is mostly known as fengcong,  and
   its hills are generally more conical than
   hemispherical in profile191. 2. A type of
   karst topography, common in the tropics,
   characterized by star-shaped depressions
   or dolines at the  feet of many steep-sided
   cone-shaped hills; narrow steeply-walled
   valleys may be present[10> 20]. A variety of
   Kegelkarst.  Synonyms: (French.) karst a
  pitons; (German.) Kegelkarst, Turmkarst;
   (Greek.) konoethes karst; (Italian.) carso
   di torri, carsismo con forme residuali
                                             46

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  coniche; (Russian.) karst s konicesklmi
  ostancami; (Spanish.) karst de conos;.,_,.
  (Turkish.) konili karst; (Yugoslavia.)
  stozasti krs, cokasti kras stozcsti, kras.
  See also cockpit karst. Compare: cupola
  karst, pinnacle karst, and tower karst.

confined. A modifier which .describes a
  condition in which the potentiomeiric
  surface is above the top of the aquifer[22].
  Synonymous with artesian.

confined aquifer.  1. An aquifer bounded
  above and below by confining units of
  distinctly lower permeability than that of
  the aquifer itself. 2. An aquifer
  containing confined ground water.
  Generally,  a confined aquifer is subject to
  pressure greater than atmospheric163.

confined water. Water separated from the
  atmosphere by impermeable rock
  stratum1161.

confining bed. A body of impermeable or
  distinctly less permeable material
  stratigraphically adjacent to one or more
  aquifers[22]. Synonymous with confining
  unit.

confining unit.  1. A hydrogeologic unit of
  impermeable or distinctly less permeable
  material bounding one or more aquifers
  and is a general  term that replaces
  aquitard, aquifuge, aquiclude[22].  2.
  Means a body of impermeable or
  distinctly less permeable material
  stratigraphically adjacent to one or more
  aquifers[22]. Synonymous with confining
  bed.

confining zone. A geological formation,
  group of formations, or part of a
  formation that is capable of limiting fluid
  movement above an injection zone[22].
  See confining unit.

confluence. Junction point of streams1161.

conformal mapping. The transposition and
  solution of plane flow problems in a
  complex plane[16].

conglomerate.  Rock consisting of large
  well rounded waterworn particles[I6].

conical wall niche. See meander niche.

conjugate joints or faults. Two sets of
  joints or faults that are formed under the
  same stress conditions (usually shear
  pairs).

conjunctive use.  The use  of both surface
  water and ground water[161.

connate water. Water entrapped in the
  interstices of a sedimentary or extrusive
  igneous rock at the time of its
  deposition1221.

consequent river. A river flowing down
  the original slope of geologic beds or
  general slope of topography[16].

conservation. The use of natural resources
  in a way that assures their continuing
  availability to future generations; the wise
  use of natural resources.

consolidation.  1. The binding of grains by
  cementing material to solid matrix1161.  2.
  The gradual reduction in the water
  content (void ratio) of a saturated soil, as
  a result of an increase in the pressure
  acting on it, because of the addition of
                                            47

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  overlying sediments or the application of
  an external load. A laboratory test
  commonly known as a one-dimensional
  consolidation test (odometric test), is
  performed on soil samples to evaluate
  consolidation. From such a test, the
  coefficient of consolidation, cv usually
  expressed in cmVsec, is calculated as the
  ratio
             Cv =
                     K- I
  where K is the hydraulic conductivity, mv
  is the coefficient of volume
  compressibility, and yw is the unit weight
  of water. The theory of consolidation
  leads to a relation between degree of
  consolidation and time:
                      c. • t
              U% =
                       H2
  In this expression U is the degree of
  consolidation or the percentage of total
  consolidation occurring in some time t; cv
  is the coefficient of consolidation; and H
  is half of the sample's thickness when the
  odometric test is performed1211.

consolidated rock. Rock that has become
  hard and coherent through compression
  and lithification[16].

constant-temperature zone. The area of a
  cave where air temperature is unchanging
  throughout the year and approximates the
  average annual temperature
  aboveground[23]. See  also zonation.

constructive waterfall.  A large rimstone
  dam on a surface stream[10].  See rimstone
  dam. Synonyms: (French.) chute
  incrustante; (German.) Wafierfall,
  inkrustierender? , Sinter...?, Sinterbecken;
  (Greek.) katarrdktis; (Italian.) (vasche
  d'incrostazione); (Spanish.) dique
  travertinico; (Turkish.) du§um;
  (Yugoslavian.) slap, precaga.

consumer. Any living thing that is unable
  to manufacture food from nonliving
  substances, but depends instead on the
  energy stored in other living things1231.
  See also carnivore; decomposers; food
  chain; herbivore; omnivore; producers.

consumptive use. The quantity of water
  used annually by crops or natural
  vegetation due to transpiration, tissue
  building, and evaporation from adjacent
      16
contact load.  The solid material in sliding
   or rolling contact with a stream bed[16].

contact spring.  See spring, contact.

contaminant. 1. An undesirable substance
   not normally present or an unusually high
   concentration of a naturally occurring
   substance in water or soil[22].  2. Any
   physical, chemical, biological, or
   radiological substance or matter in
   water[22]. See also pollutant.

contaminant plume.  An elongated body of
   ground water containing contaminants,
   emanating and migrating from a point
   source within a hydrogeologic: unit(s)[22].

contaminate. To introduce a substance that
   would cause (a) the concentration of that
   substance in the around water to exceed
   the maximum contaminant levels; or (b)
   an increase in the concentration of that
                                            48

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  substance in the ground water where the
  existing concentration of that substance
  exceeds the maximum contaminant
  levels[22].  See also pollutant.

contamination. The addition to water of
  any substance or property preventing the
  use or reducing the usability of the water.
  There is no specific limits, since the
  degree of permissible contamination
  depends upon the intended end use, or
  uses, of the water[6].  Sometimes
  considered synonymous with pollution.

continuous stream.  A stream that is
  continuous in space from source to
  discharge point[16].

contributing region.  That region which
  contributes to well discharge in inclined
  water-table flowtl6].

control. The combined effect of channel
  characteristics (area, shape, slope,
  roughness) on rating curve[16].

conulite. A hollow, cone-shaped speleo-
  them formed when a conical depression is
  drilled in cave mud by falling water.
  Subsequent erosion may remove the mud,
  isolating the calcite lining of the
  depression1103.

convective diffusion. See mechanical
  dispersion, coefficient.

convective transport.  The component of
  movement of heat or mass  induced by
  thermal gradients in ground water[22].  See
   also  advection.
convection. The process whereby heat is
  carried along with the flowing ground
  water[22].

convergence.  Net horizontal inflow of
  moisture per unit areatl6].

cooling water. Water used only for cooling
  purposes'161.

cool spring. Spring water temperature
  below mean annual surface
  temperature'161.

coprolite. The fossilized excrement of
  vertebrates such as fishes, reptiles, an
  mammals, larger than a fecal pellet,
  measuring up to 20 cm in length,
  characterized by an ovoid to elongate
  form, a surface marked by annular
  convolutions, and a brown or black color,
  and often composed largely of calcium
  phosphate; petrified excrementtl].

coprophage. A scavenger which feeds on
  animal dung, including guano[25].

coquina. Porous limestone composed of
  broken shell fragments'16].

coralloid speleothem. Any variety of
  microcrystalline, coralloid or botryoidal
  calcite deposit that is distinguished by
  curved outer surfaces and curved internal
  structures. Large examples, including
  clouds, are formed under water.  Smaller
  varieties, also known as cave coral and
  cave popcorn, are splash deposits, or are
  precipitated onto cave passage walls from
  mists or thin surface films of saturated
  water191.
                                             49

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corrasion. Mechanical erosion performed
  by such moving agents as water, ice, and
  wind, especially when armed with rock
  fragments1103. See also corrosion.

corridor. 1. Long, narrow chasm enlarged
  by action of water and into which surface
  runoff or stream may flow; may be
  located along a fault plane, fissure, joint
  or between two beds.  Struga (Slavic)
  refers to such a corridor along a bedding
  plane in a carbonate formation[20].  2.
  Relatively narrow passageway permitting
  travel between two larger areas. 3. A
  fairly level and straight passage that links
  two or more rooms or chambers in a cave.
  4. Intersecting linear depressions on the
  surface of the land, related to joints or
  dikes[I01.  See also bogaz; struga; zanjon.
  Related to chasm; bogaz. Synonyms:
   (French.) gotiffre absorbant; (German.)
  Karstgasse; (Greek.) apocheteftikos
   karstikos agogos; (Italian.) dolina
   allongata; (Russian.) coridor, hod;
   (Spanish.) callejon; (Turkish.) koridor;
   (Yugoslavian.) struga, bogaz.

 corrasion.  Abrasion of the rock floor and
   walls of a stream channel by rock debris
   carried in the water[9].

 corrosion.  1. Chemical action of water
   containing carbonic acid (also humidic,
   nitric, and other acids) on limestones and
   dolomites causing partial solution and
   related chemical changes in the rocks[20].
   2. Erosion by solution or chemical
   action1101. 3. The act or process of
   dissolving or wearing away metals[6].  See
   also accelerated corrosion; alluvial
   corrosion; corrasion; solution. Compare
   aggressive water. Synonyms: (French.)
   corrosion; (German.) Korrosion;  (Greek.)
  chemeke thiavroses; (Italian.) dissoluzione,
  corrosione; (Russian.) korrozija;
  (Spanish.) corrosion;  (Turkish.) eritme,
  yenme, kemirilme; (Yugoslavian.)
  korozija.

corrosive.  Property of aggressive water.

coupole. (French.) Cupola or hemispheric
cove. (Southern Appalachians.) Narrow
   steep-sided karst valley flanking
   limestone plateaus[10].

covered karren. Any karren that is covered
   by soil. Draining water is oversaturated
   with respect to CO2 so that corrosion is
   extensive[3].  See also wave karren; root
   karren; cavernous karren.

covered karst.  1. A fossil or currently
   developing karst in karst limestone which
   underlies superficial deposits or other
   rock, and which may produce landforms
   at the surface which reflect subsurface
   karstification1191; contrasted with naked
   karst, which is soil free. See also buried
   karst; interstratal karst; mantled karst;
   subsoil karst; sulfate-reduction karst.  2.
   A generally subdued karst landscape
   developed where carbonate rocks are
   affected by dissolutional processes
   beneath a soil cover (see bare karst)[9].
   Synonyms: (French.) karst convert;
   (German.) Bedeckter karst; (Greek.)
   kekalymenon karst; (Italian.) carso
   coperto; (Russian.) pokrytyl karst, pokritij
   karst; (Spanish.) karst cubierto; (Turkish.)
   ortulii karst; (Yugoslavian.) pokriveni krs,
   pokriti kras.
                                              50

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cow's tail. A length of rope used as a safety
  when crossing a rebelay[25].

crack. 1. Tight joint[16]. 2. A small fracture
  (i.e. small with respect to the scale of the
  feature in which it occurs).

crandallite. A cave mineral —
  CaAl3(PO4)2(OH)5-H2O[11].

crawl, crawlway. A cave passage that is
  large enough to be negotiated on hands
  and knees[10] or so small as to require a
  caver to squeeze through on his/her back
  orbellyf131.

creek, brook. Watercourse of lesser
  volume than a river.

crescentic wall niche. See meander niche.

crest lime. Line connecting crests[16].

crest segment. The top part of a
   hydrograph[16].

crest-stage indicator. A mechanical gage
   that preserves the indication of highest
   water level rise1161.

crevice.  Opening in a rock formation or
   glacier[16].

crevice karst. An  intricate irregular crevice
   system that has formed by solution
   widening of closely spaced joints.
   Crevices may be as much as 6 meters
   across and 20 meters deep. Especially
   well developed near rivers in lowland
   New Guinea1101.
critical .depth.  The depth of flow in open
  channels when specific energy is
  mimmuni[16].

critical depth flume. Venturi or Parshall
  flume for discharge measurements116].

critical flow.  Open channel flow with
  Froude Number equal to unity[16]. See
  also Froude Number.

crooked hole. Borehole deflected from the
  vertical1161.

cross bedding. Oblique deposition of thin
  beds with respect to the main planes of
  stratification1161.

cross fault. A geologic fault that is oblique
  or at right angles to the strike direction of
  the beds.

cross section. 1. Vertical section of a
   geologic profile[16].  2. A section of a cave
  passage or a chamber across its width[25].

crust stone. A fragile layer of flowstone
   covering portions of walls of caves; looks
   like a flaky crust.  Found in some
   Kentucky caves[10].

crustaceans.  The large class of animals that
   includes lobsters, crayfish, amphipods,
   isopods, and many similar forms.
   Crustaceans typically live in water and
   have many jointed appendages,
   segmented bodies, and hard
   exoskeletons[23].

 cryokarst. 1. Anon-karstic term.  Land
   surface with closed depression (usually
   small and shallow) formed by alternate
   freezing and thawing of permafrost or
                                             51

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  ground-ice overlying different rock,
  including limestone. The term 'cryokarst'
  is more common in Europe while the
  term 'thermokarst' is used in America[20].
  2. A karst-like periglacial, or formerly
  periglacial, landscape superimposed upon
  unconsolidated, superficial deposits.
  Cryokarst is characterized by small
  depressions or pits that develop due to
  settlement of overlying deposits into
  voids formed by the melting of entrapped
  ice. Also known as thermokarst[9].
  Synonyms: (French.) cryokarst,
  thertnokarst; (German.) Thermokarst,
  Cryokarst; (Greek.) thermokarst; (Italian.)
  criocarsismo; (Russian.) temokarst,
  criokarst; (Spanish.) criokarst,
  thermokarst; (Turkish.) don karsti;
  (Yugoslavian.) toplotni krs temokarst.

cryptokarst. A karst term used to describe
  (a) the result of subsurface removal of
  limestone taking place beneath permeable
  loess resulting in a loss of limestone and
  subsequent slow subsidence of the loess
  without noticeable surface expression, (b)
  the initial effects of intergranular solution
  of rock when there is practically no
  movement of water from microcavity to
  microcavity,  (c) the karst that develops in
  chalk beneath a mantle of its residual clay
  and chert, and (d) pockets in limestone
  which are filled with terra rossa or other
  residual material and which may be
  actively forming, arrested in
  development, or 'inherited'. Because this
  term has been used for at least four
  different meanings, it is recommended
  that it be  abandoned1171.

cryptozoa.  The assemblage of small
  terrestrial animals found living in
  darkness beneath stones, logs, bark, etc.
  Potential colonizers of caves[25].

crystal cave. A cave in which much of the
  surface of the roof, walls, and floor is
  covered with well-formed mineral
  crystals[10].                  ;

crystal pool. In caves a pool, generally
  having little or no overflow, containing
  crystals1101.                  ;

cuesta, hogback. A nonsymetrical ridge
  due to a gently dipping straturrp61.

cueva. (Spanish.) Cave, especially one that
  is horizontal or nearly so[10].

cul-de-sac; dead end.  A subterranean pas-
  sage having only one entry[10].

cumulative production.  The sum total of
  volumetric discharge of a well since
  production began[16].

cupola. A hemispheric hill of limestone1101.
  See also  cone karst; cupola karst; mogote;
  pinnacle karst; tower karst. Synonyms:
  (French.) cupole; (German.) Halbkugel.

cupola karst.  A type of karst topography
  common in the tropics in which the
  residual hills rise in hemispherical or
  dome-capped mounds from intervening
  depressions or sinkholes[201. See also
  cone karst; cupola; pinnacle karst; tower
  karst.  Synonyms: (French.) karst a
  cupules,  coupole; (German.) Kegelkarst;
  (Greek.) konoidhes karst; (Italian.)
  carsismo con forme residnali a  cupola;
  (Spanish.) karst de cupulas; (Turkish.)
  kubbeli karst; (Yugoslavian.) kupolni krs
  (kras).                      i
                                             52

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cupula (plural cupulae). A jellylike rod
  projecting into the water from a      t,
  neuromast, part of a fish's or amphibian's
  lateral line system.  Vibrations in the
  water cause the cupula to move, thus
  setting off nervous impulses that enable
  the animal to detect nearby movements in
  the water[23]. [Not to be confused with
  cupola.]

current marking.  Shallow asymmetrical
  hollows, caused by turbulent waterflow,
  that are distributed in rather regular
  fashion over limestone surfaces[10]. See
  also scallop.

current meter, current counter. A device
  used to measure the current velocity
  directly at a given point[16]. Synonym:
  ammeter.

curtain.  1. Sinuous, thin sheet (or sheets) of
  dripstone formed on the roof or walls of a
  cave or behind a waterfall[20]. 2.  A wavy
  or folded sheet of flowstone hanging from
  the roof or projecting from the wall of a
  cave; often translucent and resonant[10].
  See also bacon; blanket; drapery. Related
  to helictite and speleothem. Synonyms:
  (French.) draperie stalagmitique;
  (German.) Sinterfahne; (Greek.)
  parapetasma stalaktitikon; (Italian.)
  cortina stalattitica; (Russian.) zanavesj;
  (Spanish.) bandera, cortina; (Turkish.)
  perde; (Yugoslavian.) sigqsta zavjesa,
  sigasta zavesa.

curve, backwater.  A water surface profile
  in a stream or channel above a
  constriction or impoundment^61.

curve, concentration. The rising limb on a
  hydrograph curve[16].
curve, desorption.  Curve of moisture
  content verses soil moisture tension1 16].

curve, drawdown.  A plot of drawdown
  with radial distance from a well[16].

curve fitting.  The fitting of experimental
  data points to a theoretical type curve[16].

cutter. 1. (Tennessee.) Solution crevice in
  limestone underlying residual phosphate
  deposits.  2. A karren-like groove formed
  beneath the soil, more commonly referred
  to as subsoil karren[I01. See also karren.

cuttings.  Rock chips loosened from the
  bottom of a borehole by drilling1161.

cyanotrichite.  A cave mineral —
cycle.  Regular periodic occurrence of an
   event[i6].
                                             53

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                   D
dam. A structure across a watercourse that
  impounds water; may be natural or
  artificial1161.

damping. The process of gradually
  reducing amplitude of aperiodic event
  such as acoustic oscillations in velocity
  logging'161.

dargecit. See aisle.

Darcian velocity; seepage velocity. See
  specific discharge.

Darcy's law.  An empirical law given as
                        ,dh
              Q  =  -KA
                        dL
   which states that the average volumetric
   discharge of flow through a porous
   medium is directly proportional to the
   hydraulic gradient assuming that the flow
   is laminar and inertia can be neglected.
   Note: <2=discharge, ^hydraulic
   conductivity, ^4=cross-sectional area,
   G?/z/tfL=gradient, and a minus sign is
   attached as a convention to indicate that
   flow occurs in the direction of decreasing
   head'51.

Darcy unit. A practical unit for the measure
   of intrinsic permeability1161.

Darcy-Weisbach equation.  An empirical
   equation given as
            Q =  -A.
                    \
SRgdh
 f  dL
  which states that in contrast to laminar
  flow, the average volumetric discharge of
  flow is directly proportional to the square
  root of the driving force and that the
  friction loss is equal to the hydraulic
  head[5]. Note: g=discharge, ^-cross-
  sectional area, J?=hydraulic radius of the
  conduit, g=gravitational acceleration,
  y=some friction factor, J/z/d^gradient,
  and I have attached a negative sign to
  indicate that ground-water flow occurs in
  the direction of decreasing head,  m most
  instances, a negative sign is not included
  because it is not possible to take the
  square root of a negative number.

dark adaptation. A change in the retina of
  the eye sensitizing it to dim light (the eye
  "becomes accustomed to the dark")[25].
  Compare light adaptation.    ;

dark zone. The part of a cave which
  daylight does not reach[25].

dating of cave sediments. Determination
  of the age of development of caves is
  normally impossible.  Only the sediments
  they contain can be dated, and these must
  necessarily be younger than the
  containing passage.  Geomorphological
  correlations may allow more accurate
  dating of the cave erosion. The most
  useful dating method in current use is
  based upon a knowledge of the rates of
  decay of radioactive isotopes of uranium
  to thorium in stalagmites.  This technique
  allows measurement of ages in material
  up to 350,000 years old. Dating of
  stalagmites has confirmed that many cave
  ages lie beyond this range. Electron spin
  resonance (ESR) measures the cumulative
  effects of radiation that are partly a
  function of time and can give stalagmite
                                            54

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  ages back to about 900,000 years.
  Palaeomagnetism may recognize events
  up to 2 million years old, but a sequence
  of palaeomagnetically dated sediments is
  required to allow identification of the
  actual ages191.

datum plane. A reference level to which
  topographic or water ley-els-in wells are
  .related[16].

daylight hole. A hole in the roof of a cave,
  reaching the surface[10].

dead cave. A dry cave in which all solution
  and precipitation has -ceasedI10].

dead end.  See cul-de-sac.

dead water.  Standing, stagnant water[16].

debris.  1. Any material found to have been
  washed into a cave from some other
   locality. 2. Coarse rock fragments
   resulting from erosion and disintegration
   ofbedrock[16].

debris karren. These are pinnacles that
   form in limestones with a thin sheet
   structure that soon fall into smaller
   fragments131. See also pinnacles.

decalcification. Removal by solution of the
   calcium carbonate constituents from a
   rock or sediment, leaving a residuum of
   noncalcareous material^'21]. Synonyms:
   (French.) decalcification; (German.)
   Losungsruckstand (Entkalkung); (Greek.)
   exasvestoses; (Italian.) decalcificazione\
   (Russian.) dekaljcifikacija', (Spanish.)
   decalcificacion; (Turkish.) karbonatini
   giderme; (Yugoslavian.) dekalcijikacija.
Deckenkarren.  (German.) Solutional
  pendant features in cave ceilings[10].

declination.  The angle from true (or grid)
  north to magnetic north for a given time
  and place[25].

declogging. The cleaning of clogged well .
  surface or screens1^61.

decomposers. Living things, chiefly
  bacteria and fungi, that live by extracting
  energy from the decaying tissues of dead
  plants and animals.  In the process, they
  also release simple chemical compounds
  stored in the dead bodies and make them
   available once again for use by green
  plants[23].

decoration.  Cave features due to secondary
   precipitation of calcite, aragonite,
   gypsum, and other rarer minerals.

deep percolation.  The drainage of soil
   water downward by gravity below the
   maximum effective depth of the root zone
   toward storage in subsurface strata[221.

deflocculation. The breakup of floes of gel
   structures by use of a thinner[6].

deformation. Changing of form, volume,
   and relative position of rock masses[16].

 degradation. 1. Geological action of
   wearing down a surface[16]. 2. the process
   of degrading water quality in an aquifer
   by the addition of contaminants, either
   naturally or artificially. 3. The process by
   which various chemicals are altered to
   form new chemicals; breakdown.
                                             55

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degree of cementation. The degree to
   which a rock has been solidified due to
   cementation[16].

degree of karstification. The ratio of the
   volume of openings to the total volume of
   a soluble massif, expressed as a
   percentage. It is the sum of the activity
   indices from the initiation of
   karstification, and so is normally applied
   only to carbonate rocks with little or no
   primary porosity1203. Related to corrosion
   and solution. Synonyms:  (French.) taux
   de karstification; (German.) Ausmafl
   (Grad) der Verkarstimg; (Greek.) vathmos
   karstikiiseos; (Italian.) grado di
   carsificazione; (Spanish.) grado de
   karstiflcacion; (Turkish.) karstla§ma
   derecesi; (Yugoslavian.) stupanj krskog
  procesa, stopnja zakrasevanja, stepen
   karstifikacije.

degree of saturation. See percent
   saturation.

delay. The lapse time between signal
   emission and signal reception in seismic
   logging1'61.

delta. A triangular deposit of sediments at
   the inflow of a river into an ocean or
   lake'161.

demand.  The rate of draft from an aquifer
   or reservoir to meet a certain demand[16].

demineralization. The removal of mineral
   matter from water[16].
dendritic.  Tree-like pattern1161.

dendritic drainage pattern.  A drainage
  pattern in which the streams branch
  randomly in all directions and ;at almost
  any angle, resembling in plan the
  branching habit of certain trees.  It is
  produced where a consequent stream
  receives several tributaries which in turn
  are fed by smaller tributaries. : It is an
  indicative of insequent streams flowing
  across horizontal and homogeneous strata
  or complex crystalline rocks offering
  uniform resistance to erosion.' This
  pattern may form on top of the land
  surface or below the land surface in karst
  aquifers with anastomoses forming the
  smaller tributaries.

density.  The mass of water per unit volume,
  usually stated in grams per cubic
  centimeter (gm/cm3), but may also be
  measured in pounds per gallon (Ib/gal),
  pounds per cubic foot (lb/ft3), and
  kilograms per cubic meter (kg/m3.)
  Density of fresh water is taken to be 1.0.

density current.  A gravity-induced flow of
  one current through, over, or under
  another, owing to density differences.
  Factors affecting density differences
  include temperature, salinity, and
  concentration of suspended particles.

denudation. The wearing away of
  overlying loose rock to top of bedrock[16].
                              i

denuded karst. Subsoil karst or interstratal
  karst which has been exposed by erosion
  of its covertl?].  See also exposed karst;
  interstratal karst; subsoil karst
  Synonyms: (French.) karst denude;
  (German.) nackter Karst, oberfldchlicher
  Karst; (Greek.) apogymnomenpn'karst;
  (Italian.) carso denudato, carso nudo;
  (Russian.) golij karst, otkritij karst;
  (Spanish.) karst denudado; (Turkish.)
                                            56

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  belirgin karst; (Yugoslavian.) ogoljeli kfs
  (krds), goli kfs(krds), razkriti kras.   ^

depletion. The withdrawal of water at a
  .greater rate than replenishment^61.

deposition factor. The factor that describes
  the settling of suspended solids within
  pore space[16].

depression.  A small hollow in a surface1161.

depression spring.  See spring, depression.

depth gage.  1. Any device used to measure
   depths such as water level in wells[16].  2.
   Specific gage for measuring river stage[16].

depth of penetration,  hi electrical
   resistivity surveys, it is the depth to which
   an electrical field penetrates into the
   subsurface as a function of electrode
   spacing1161.

 desalimization. The process of salt
   removal[16].

 desander. A device used to separate sand
   from well water™.

 descender.  A mechanical device for
   descending ropes[25].

 desert.  1. Region where precipitation is less
   than 10 inches per year.  2. Region where
   the net moisture inflow is too small to
   support vegetation[16].

 desiccation. The removal of moisture by
    evaporation or drying1161.
desiccation crack.  A crack formed in soil
  as a rpsult of shrinkage to a drying
  volume^61.

desorption. The reverse process of
  sorption[22]. See also sorption.

detritus.  Loose material originating from
  disintegrated and weathered rock[16].

developed section. The result of
  straightening out a section composed of
  several parts with differing directions into
  one common plane. Usually the plane is
  vertical and the length of the section
   equals the plan lengths of the passages
   and chambers comprising1251.

development. The act of repairing damage
   to the formation caused by drilling
   procedures and increasing the porosity
   and permeability of the materials
   surrounding the intake portion of the
   well[61.

 deviation. 1. Deflection of a recording from
   a base line (e.g., the deviation from
   vertical of a borehole)[16]. 2. Usually a
   sling of rope or tape attached to a natural
   anchor at one end and clipped to the rope
   with a karabiner at the other. Used to
   avoid rub points on pitches1251. Synonym:
   redirection.

 dew-point.  The point at which dew
   formation starts for given temperature and
   humidity conditions[16].

 D-horizon.  The zone of bedrock in a soil
   horizon[16].

 diagenesis. Post depositional physical and
    chemical changes in sediment1161.
                                               57

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diatomaceous earth.  A light-colored, soft,
  siliceous earth composed of the shells of
  diatoms, a form of algae.  Some deposits
  are of lake origin but the largest are
  marine[6].

differential water capacity.  The absolute
  value of the rate of change of water
  content with soil water pressure. The
  water capacity at a given water content
  will depend on the particular desorption
  or adsorption curve employed.
  Distinction should be made between
  volumetric and specific water capacity1221.

diffuse circulation;  diffuse flow.
  Circulation of ground water in karst
  aquifers (or other  aquifers) under condi-
  tions in which all, or almost all, openings
  (primary and secondary) in the karstified
  rock intercommunicate and are full of
  water but have not been selectively
  enlarged in specific zones by dissolution,
  and so thus no concentration of ground
  water occurs in restricted conduits[9>21].
  The ground-water flow is generally slow-
  moving, may be laminar, and have a
  uniform discharge and slow response to
  storms. It is being replaced by the term,
  slow flow, because significant confusion
  regarding its usage especially when
  thought of as in terms of porous-media
   flow.  Synonyms: (French.) circulation
   diffuse; (German.) Diffuse
   GnmdwaJSerbewegung; (Greek.)
   thiacheomenon ydhor; (Italian.)
   circolazione carsica diffusa; (Spanish.)
   circulation saturada difusa; (Turkish.)
  yaygin dola^vn; (Yugoslavian.) difuzno
   tecenje.

diffusion. Process whereby ionic or
   molecular constituents move under the
  influence of their kinetic activity in the
  direction of their concentration
  gradient1221.                   ;

diffusion coefficient. See molecular
  diffusion, coefficient.         ;

diffusion, convective.  See mechanical
  dispersion, coefficient.        I

diffusivity, soil water. The hydraulic
  conductivity divided by the differential
  water capacity (care being taken to be
  consistent with units), or the flux of water
  per unit gradient of moisture content in
  the absence of other force fields1221.

diffusivity, hydraulic. The ratio of
  transmissivity divided by the storage
  coefficient or the hydraulic conductivity
  divided by the specific storage1221.

dig. An excavation made to discover or
  extend a cave or to uncover artefacts or
  animal bones[25].             ;

dike. 1. A wall or embankment protecting
  lowlands from being flooded1161. 2. A
  subsurface sheet-like igneous  intrusion
  into bedrock fractures[161.     ;

Dinaric Karst.  The extensive expanse of
  karst landscape stretching from Italy,
  across the whole of southern Slovenia and
  Croatia, into parts of south-west Bosnia
  and across Montenegro, ultimately
  extending into Albania and Greece191.

dip. 1. The angle between an inclined
  bedding plane in a rock sequence and the
  horizontal.  The dip value includes an
  inclination and a direction and the two
   components are generally quoted in this
                                             58

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  order and in the format 10° ENE or 10°
  towards 025° magnetic (etc.). The dip
  direction is down the slope. True dip is
  the maximum dip value of a given
  bedding plane; other, lesser values,
  obliquely down the same bedding plane,
  referred to as apparent dips.  The
  direction at right-angles to the true dip,
  where the dip value is zero, is known as
  the strike[9].  2. Maximum plunge of
  sloping planar features  (e.g bedding,
  fractures) within a geological formation
  measured perpendicularly to the strike of
  the features.  See also strike; hade.

dipmeter survey. A geophysical borehole
  logging method where the dip of the
  penetrated strata is measured[16].

diphenyl brilliant flavine 7GFF, direct
  yellow 96.  A yellowish dye initially
  developed to color tennis balls and
  subsequently shown to be useful in
  environmental tracing studies. Dye type:
  Stilbene. See also fluorescent dyes.

discharge. The volumetric flow of water
  through a given cross section[16].

discharge area. An area in which ground
  water is discharged to the land surface,
  surface water, or atmosphere1221.

discharge, evaporation.  The direct
  discharge of ground water to the
  atmosphere by evaporation1163.

discharge, hydraulic.  The discharge of
  ground water through springs or wells[16].

discharge, maximum.  The maximum
  discharge of a river or spring during high
  flow conditions[16].
discharge, natural. The discharge of water
  into surface water bodies or springflow[16].

discharge hydrograph. A graph showing
  the discharge of water as a function of
discharge pipe.  A pipe through which a
  pump discharges^163.

discharge pressure. The pressure at which
  a certain discharge takes place[I6].

discharge velocity. The rate of discharge of
  water through a porous medium per unit
  of total area perpendicular to the direction
  of flow.

disconformity. A geological unconformity
  between parallel beds, often with some
  series missing[16].

discontinuity.  1 . A point where a
  mathematical function becomes
  nondefmed[16].  2. An unconformity in
  which the bedding planes above and
  below the break are basically parallel,
  indicating a significant hiatus in the
  orderly sequence of sedimentary rocks. 3 .
  A surface at which seismic-wave
  velocities abruptly change.

discontinuity surface. Any surface across
  which some property for a rock mass is
   discontinuous. This includes fracture
   surfaces, weakness planes, and bedding
  planes but the term should not be
  restricted only to mechanical continuity.

dispersion. The spreading and mixing of
   chemical constituents in ground water
   caused by diffusion and mixing due to
                                            59

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  microscopic variations in velocities
  within and between pores[6].

dispersion coefficient.  1. A measure of the
  spreading of a flowing substance due to
  the nature of the porous medium, with its
  interconnected channels distributed at
  random in all directions[22]. 2. The sum of
  the coefficients of mechanical dispersion
  and molecular diffusion in a porous
  medium1221.

dispersion, longitudinal. Process whereby
  some of the water molecules and solute
  molecules travel more rapidly than the
  average linear velocity and some travel
  more slowly which results in spreading of
  the solute in the direction of the bulk
  flow'22'.

dispersion, mechanical. See mechanical
  dispersion.

dispersion, transverse.  Spreading of the
  solute in directions perpendicular to the
  bulk flow[22].

dispersion zone.  A zone of intermixing in
  miscible flow or in sea water
  encroachment. See also transition
  zone'16'.

dispersivity.  A geometric property of a
  porous medium which determines the
  dispersion characteristics of the medium
  by relating the components of pore
  velocity to the dispersion coefficient^21.

displacement. 1. The process of replacing
  one fluid in a porous medium by
   another1161. 2. A change in position of a
  material point. See also miscible
   displacement.
disposal well. A well used for the disposal
  of waste into a subsurface stratum. See
  also injection well[22].

dissociation. A chemical process that
  causes a molecule to split into simpler
  groups of atoms, or ions. For example,
  the water molecule (H2O) breaks dov/n
  spontaneously into H+ and OH" ions[6].

dissolution.  See solution.

dissolution of limestone.  The solubility of
  calcite (and hence of limestone) in pure
  water is very low, but is vastly increased
  in the presence of carbon dioxide. This
  gas, dissolved in the water to produce
  carbonic acid, permits dissociation of
  calcium  carbonate, and dissolution rates
  and loads are therefore directly related to
  carbon dioxide content.  This accounts for
  the importance to limestone dissolution of
  plant growth; soil water contains greatly
  more carbon dioxide than stream waters.
  Further dissolution occurs due to mixing
  of saturated waters of different carbon
  dioxide content (see
  Mischungskorrosion), because of a non-
  linear relationship between carbonate
  saturation and carbon dioxide Content.
  This process is of major significance to
  continued dissolution within the phreas.
  Cold water can dissolve more carbon
  dioxide but, with respect to cave
  development, this climatic factor is
  overwhelmed by the higher organic
  activity producing more carbon dioxide in
  warmer  environments.  Loss of carbon
  dioxide, by diffusion into open air, causes
  water to precipitate calcite as
   speleothems. Limestone dissolution may
   also be achieved by organic acids or by
   strong acids, particularly sulphuric acid,
                                             60

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  though such effects are normally far less
  than that of carbon dioxide.  Strong acid
  dissolution is probably involved in the
  inception of most underground drainage.
  Dissolution by sulphuric acid formed by
  oxidation of sulfide minerals or gases
  may be a major cave-forming process in
  some regions, and was largely responsible
  for the enlargement of Carlsbad Caverns
  and Lechuguilla Cave, New Mexico[9].

dissolution zone. A laterally extensive zone
  where extensive dissolution of bedrock
  has occurred.

distortion. A change in shape of a solid
  body.

distribution coefficient. The quantity of
  the solute, chemical, or radionuclide
  sorbed by the solid per unit weight of
  solid divided by the quantity dissolved in
  the water per unit volume of water1221.

distribution, frequency. Distribution of the
  number of occurrences of a variate.

disturbance. In geology, any change of the
  original position of rocks by folding^161.

disturbed sample. A sample disturbed with
  respect to its original mode of packing
  and sedimentation (e.g., a drill core)[16].

divide.  1. A line connecting the highest
  topographic elevations or ground-water
  crests that separate one drainage basin
  from anothertl6]. 2. A ridge in the water
  table or potentiometric surface from
  which the ground water represented by
  that surface moves away in both
  directions. Water in other aquifers above
  or below, and even in the lower part of
   the same aquifer, may have a
   pptentiometric surface lacking the ridge,
   and so may flow past the divide.  See also
   ground-water divide; water-table divide.
   Synonyms: ground-water divide; ground-
   water ridge; water-table divide. 3. (a) The
   line of separation, or the ridge, summit, or
   narrow tract of high  ground, marking the
   boundary between two adjacent drainage
   basins or dividing the surface waters that
   flow  naturally in one direction from those
   that flow in the opposite direction; the
   line forming the rim of or enclosing a
   drainage basin; a line across which no
.   water flows. 3. (b) A tract of relatively
   high  ground between two streams; a line
   that follows the summit of an interfluve[I].
   See also drainage divide.

DNAPL.  Abbreviation for dense
   nonaqueous phase liquid. Liquids falling
   into this category have specific gravities
   greater than water (the specific gravity for
   water is usually taken to be one),  are
   relatively immiscible with water,  and tend
   to migrate downwards through the vadose
   and phreatic zones in a relatively
   unimpeded manner.  See also LNAPL;
   immiscible; NAPL.

dog-tooth crystal; dog-tooth spar.  A
   variety of calcite in the form of sharp-
   pointed crystals[10].

doline;  sinkhole. A basin- or funnel-shaped
   hollow in limestone, ranging in diameter
   from a few meters up to a kilometer and
   in depth from a few  to several hundred
   meters. Some dolines are gentle grassy
   hollows; others are rocky cliff-bounded
   basins.  A distinction may be made by
   direct solution of the limestone surface
   zone, (solution dolines), and those formed
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by collapse over a cave, (collapse
dolines), but it is generally not possible to
establish the origin of individual
examples1101.  Solutional enlargement is
either circular in plan, if there is one
dominant vertical joint, or otherwise
irregular if there are several and can
achieve dimensions of up to 1,000 meters
in diameter and 100 meters deep. Where
a karst bedrock is covered by superficial
deposits, solutional enlargement permits
the latter to subside into vertical fissures,
creating subsidence cones or alluvial
dolines, whose slopes are unstable
because of the unconsolidated nature of
the surface material. The bedrock
remains covered in the first instance.
Dolines are also formed by the large-scale
subsidence caused by cave roof-collapse
of near-surface caverns; in this instance,
the collapse doline, the sides are cliff-like
and the floor composed of the irregular
blocks from the  fragmented roof. Cave
roof-collapse is considered a relatively
rare phenomenon. Closed depressions
receiving a stream are known as swallow
holes or stream sinks.  A doline which is
largely dependent upon snow for
solution-enlargement is known as a kotlici
or Schneedoline[l9]. hi America most
dolines are referred to as sinks or
sinkholes.  See also jama; pit; ponor;
sink, sinkhole; stream sink; swallet;
swallow hole; sumiderb.  Synonyms:
(French.) doline; (German.) Dolmen,
Karsttrichter; (Greek.) tholene; (Italian.)
dolina, pozzo naturale; (Russian.)
karstovaja voronka, karstovaja kotlovina;
(Spanish.) dolina; (Turkish.) duden,
kokurdan, huni; (Yugoslavian.) vrtaca,
ponikva, dolac, do, duliba, kotlic, konta.
doline karst. Karst dominated by closed
  depressions, chiefly dolines, perforating a
  simple surface[25].

doline lake. A small karst lake occupying a
  doline or closed depression in limestone.
  The term implies that the doline is at or
  near the ground-water table arid in
  hydrological continuity with it, or that the
  base of the doline is sealed with an
  impermeable layer such as clay1203.  See
  also sinkhole pond. Synonyms: (French.)
  lac de doline; (German.) Dolinensee;
  (Greek.) limni dholina; (Italian.) lago di
  dolina,  lago carsico; (Russianl) karstovoe
  ozero; (Spanish.) dolina laguna, torca
  laguna; (Turkish.) obrukgolu;
  (Yugoslavian.) krskojezero, kraskojezero.

dolomite.  1. The pure mineral dolomite has
  the composition CaMg(CO3)2 and has
  properties very similar to those of calcite.
  The rock dolomite consists mainly of the
  mineral dolomite, with subordinate
  calcite, and has properties very similar to
  those of limestone. The natural
  dissolution of dolomite is generally
  slower than that of limestone.; Hence,
  dolomite karst is generally less well
  developed than limestone karst, though
  exceptions do occur in areas such as
  north-west Canada. Large, deep caves
  can form in dolomite, as in the Rand of
  South Africa[9].  2. A mineral composed
  of calcium magnesium carbonate,
  CaMg(CO3)2. 2. Rock chiefly composed
  of the mineral dolomite[10]. Also called
  dolostone.

dolomitic limestone. A limestone
  containing a significant proportion of the
  mineral dolomite but in which calcite is
  more abundant (e.g. 10-45% dolomite,
                                          62

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  90-55% calcite). Many dolomitic
  limestones originate as calcite limestone
  that is subsequently affected by
  magnesium-rich water that replaces part
  of the calcite with dolomite[9].

dolomitic flour (sand).  A loose mealy rock
  or residuum, produced by the
  disintegration of dolomitic limestones
  under the processes of karstification[20].
  Synonyms: (French.) sable dolomitique;
  (German.) Dolomitsand, Dolomitasche;
  (Greek.) dholomitikon alevron; (Spanish.)
  arena dolomitica; (Turkish.) dolomit
  kumu; (Yugoslavian.) dolomitni pijesak, d.
  pesak, d.pesek.

dolomitization. The process whereby
  limestone becomes dolomite by the sub-
  stitution of magnesium carbonate for part
  of the original calcium carbonate1101.

domain. A biological region of the earth's
  crust[25].

dome.  1. A high  shaft in a room or passage
   formed by solution031. 2. A large
  hemispheroidal hollow in the roof of a
   cave,formed by the breakdown and/or salt
  weathering, generally in mechanically
   weak rocks, which prevents bedding and
  joints dominating the form[25]. See also
   dome pit.

dome pit. 1. American term defined by
   Davis (1930) 'Mammoth Cave possesses
   several extraordinary vertical cavities of
   which the arched tops are called domes
   and the deep bottoms are called pits. The
   combined name, dome pits, is here used
   for them'. 2. A deep shaft in a cave,
   intersected by  a passage at or near its
   mid-section[20]. See aven. Synonyms:
  (French.) evorsion, marmite inverses;
  (German.) Deckenkolk; (Greek.) vathis
  lakkds me tholon; (Italian.) marmitta
  inversa; (Spanish.) marmita inversa;
  (Turkish.) kemerli obruk.

donga,  hi the Nullarbor Plain, Australia, a
  shallow, closed depression, several meters
  deep  and hundreds of meters across, with
  a flat clay-loam floor and very gentle
  slopes1251.

double  brake bars. A rappel device used
  by cavers that consists of two carabiners
  with  a brake bar on each and connected
  together with another carabiner or a metal
  ring1131.

downwarping. A down bending of stratum
  to form a depression or syncline[161.

drag. The resistance force of flowing fluid
  on a  solid boundary1161.

drainage area. A horizontal projection of
   an area drained by a particular river
   system[16].

drainage basin. The land area from which
   surface runoff drains into a stream
   channel or system of stream channels, or
   to a lake, reservoir, or other body of
   water[6]. In a karst setting, subsurface
   drainage (internal drainage) may have
   boundaries defined on the basis of
   comprehensive ground-water tracing
   studies. See also ground-water basin.

 drainage density.  A ratio of total channel
   segments lengths cumulated for all orders
   to basin area[16].
                                             63

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 drainage ditch. A small channel through
   which surface water can drain[16].

 drainage divide. The rim of a drainage
   basintl<5J. See also divide; ground-water
   divide; water-table divide.

 drainage network. A system of streams
   and rivers draining a given basin[16].

 drainage pattern.  A geometric
   arrangement of stream segments in a
   drainage system[16].

 drainage ratio. A ratio of runoff to
   precipitation[I6].

 drainage system. A network of streams and
   tributaries[16].

 drainage well. 1. A well installed to drain
   surface water, storm water, or treated
   waste water into underground strata[22]. 2.
   A water well constructed to remove
   subsurface water or to reduce a
   hydrogeologic unit's potentiometric
   surface1221.

 drain tile; french drain. A porous pipe
   used for collection of excess ground
   water[16].

 drapery. A thin sheet of dripstone, equiv-
   alent to curtain[IO]. See also bacon;
   blanket; curtain.

draw.  A natural depression or small
   valley^.

drawdown.  1. The vertical distance the
   water elevation is lowered or the
   reduction of the pressure head due to the
   removal of water[22].  2. The decline in
   potentiometric surface at a point caused
   by the withdrawal of water from a
   hydrogeologic unit[22].       :

 drawdown curve.  A plot of drawdown
   with radial distance from a well[16].

 driphole.  1. Hole in rock or clay produced
   by fast-dripping water. 2. Hollow space
   surrounded by precipitated material., such
   as the bottom of a stalactite1101,.

 dripline. A line on the ground at a cave
   entrance formed by drips from the rock
   above. Useful in cave survey :to define
   the beginning of the cave[25].  ;
                              |
 dripstone.  Calcium carbonate deposited
   from water dripping from the peiling or
   wall of a cave or from the overhanging
   edge of a rock shelter; commonly refers to
   the rock in stalactites, stalagmites, and
   other similar speleothems; in some places
   composed of aragonite or gypsum[10].
   Synonyms: (French.) concretions;
   (German.) Tropfstein, Stalagrhit, Stalaktit;
   (Greek.) stalaktitis, stalagmitis; (Italian.)
   concrezione; (Russian.) kapeljnik;
   (Spanish.) concrecion (estalagmitjca o
   estalactitica); (Turkish.)  damlata^i;
   (Yugoslavian.) sige, smugori.', See also
   flowstone.

drowned karst.  Karst topography that is
   submerged by a change in sea level or
   lake level. Synonym: karst ndye.  See
   also subaqueous karst.       ;

drowned spring.  See spring, drowned.

drought. A period of moisture deficiency
   and absence of water for plant ;growm[16].
                                            64

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dry cave. A cave without a running
   stream1101.  See also dead cave.

dry hole. A hole not obtaining any
   production. A non-producing well[16].'

dry valley.  1. Valley that lacks a permanent
   surface stream.  Dry valleys are common
   on carbonate rocks with good primary
   permeability and occur on other
   permeable rocks such as sandstone. Dry
   valleys on cavernous limestone were
   formed when streams flowed on the
   surface, either before secondary
 • permeability and cave systems developed,
   or when caves were blocked by ground
   ice in periglacial climates. The valleys
   became dry when underground drains
   formed or were re-opened, capturing first
   part and then all of the surface drainage[9].
   2. A valley that lacks a surface water
   channel; common in the chalk of southern
   England[10]. 3. Elongated recesses and
   valleys at the bottom of which are
   dolines, jamas and caves.  4. A valley
   form of fluvial or periglacial origin in
   which surface drainage is intermittent or
   totally absent.  Fossil, usually with steep
   scree slopes, it is variously identifiable as
   a product of nival processes or higher
   water tables subsequently lowered by
   allogenic valley1191. Synonyms: (French.)
   vallee seche; (German.) Trockental;
   (Greek.) xera Mas; (Italian.) valle morta,
   valle asciutta; (Russian.) suhaja dolina;
    (Spanish.) valle seco; (Turkish.) kuru
   vadi; (Yugoslavian.) suha dolina.

 duck; duck-under.  1. A place where water
    reaches the cave roof for a short distance
    and can be passed by quick submergence
    without swimming. 2. In cave diving,  a
    longer stretch of passage where the water
  is so close to the roof that crawling or
  swimming beneath the water surface is
  needed to pass[10].

dug well. A hand excavated well[16].

dune limestone. (Australian.) See eolian
  calcarenite.

Dupuit's assumption. A simplifying
  assumption for the solution of a free
  surface well flow problem[16] (e.g. a
  water-table aquifer.) It is based on the
  assumption that the slope of the phreatic
  surface is negligibly small so that the
  equipotential lines are vertical and flow is
  essentially horizontal.

duration curve.  A cumulative frequency
   curve of a continuous time series of
  hydrologic parameters1161.

Durchgangshohle. (German.) See through
   cave.

dye gaging. See tracer gaging.

 dye test. Determination of direction and
   rate of flow of streams by marking them
   with dye at the infiltration area and then
   identifying and timing the reappearance
   of color at lower-lying springs, in river
   beds and elsewhere in a cave system[20].
    Synonyms: (French.) coloration;
    (German.) Farbung, Farbversuch;
    (Greek.) chrostike ichnithetesis; (Italian.)
    tracciamento con colorante; (Russian.)
    method krasjascih,  indikatorov; (Spanish.)
    coloracion; (Turkish.) boya deneyi;
    (Yugoslavian.) bojenje, barvanje. See
    also tracer.

 dynamic phreas.  See phreas, dynamic.
                                              65

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dynamic similarity. A scaling procedure of
  model and prototype where the
  relationship of dynamic parameters is
  retained[16].

dynamometer.  A device used to measure
  the momentum force of a stream
  velocity[16].
                                         66

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                    E
Easting. 1. The distance of a point east of
   the point of origin of the grid of a map or
   some abbreviation of it[25].  2. The
   west-east component of a survey leg, or
   of a series  of legs or of a complete
   traverse; east is positive and west is
   negative[25].

ebb-andl-flow spring; ebbing-and-flowing
   well. See  spring, ebb-and-flow.

eccentric. Adjective or noun implying
   abnormal shape in speleothems, such as
   helictites[10].

eccentric well. A well that is not in the
   center of the radius of influence[16].

ecology. The scientific study of the
   relationships of living things to one
   another and to their environment.  A
   scientist who studies these relationships is
   an ecologist[23].

eddy. A non-laminar circulation of fluid at
   boundaries of flow separation1161.

effective abstractions. The difference
   between total precipitation and effective
   precipitation[16].

effective diameter. A 10 percentile size
   (i.e. 10% diameter smaller than this
   diameter)[16].

effective hydraulic conductivity. See
   hydraulic  conductivity, effective.

effective porosity. See porosity, effective.
effective precipitation. That part of
  precipitation that contributes entirely to
  direct runoff.

effective rainfall.  Effective precipitation
  when only rainfall is involved[16].

effective size. The 90%-retained size of a
  sediment as determined from a grain-size
  analysis; therefore, 10% of the sediment
  is finer and 90% coarser[6].

effluent.  1. The discharge of water or other
  fluids from a spring.  2. A waste liquid
  discharge from a manufacturing or
  treatment process, in its natural state or
  partially or completely treated, that
  discharges into the environment^61.

effluent cave.  See outflow cave.

effluent stream.  See gaining stream.

elastic limit. The point on a stress/strain
  curve at which transition from elastic to
  inelastic behavior takes place.

elastic properties. The properties
  describing deformation of a solid[16].

elasticity. The property of a material that
   allows the material to return to its original
   form or condition after the applied force
  has been removed.

electric lamp.  As used in caving, generally
   a helmet-mounted headpiece (bulb,
   reflector, and lens) with a wire running to
   a battery carried elsewhere on the
   person1
         [13]
                                              67

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 electro-chemical gaging. Flow
   measurement based on electric detection
   of electrolyte tracer flow[I6].

 electrolyte. A chemical which dissociates
   into positive and negative ions when
   dissolved in water, increasing the
   electrical conductivity^1.

 elutriation. A washing process by
   decantation with water[16].

 embankment. A natural or artificial lateral
   boundary of a river[16].

 embryo.  A developing individual before its
   birth or hatching1231.

 emergence. A general term for the
   outflowing water, for the opening or for
   the area of outflow of a karst spring;
   includes exsurgence and resurgence[20].
   Synonyms:  (French.) emergence;
   (German.) Ausfluptelle, Karstquelle;
   (Greek.) pighdzon ythor (or kephalari);
   (Italian.) risorgenza; (Russian.) vihod
   karstovih vod; (Spanish.) fuente,
   manantial, surgencia; (Turkish.) yuzeye
   eri$im; (Yugoslavian.) krsko vrelo, krski
   izvor, obrh.  See also exsurgence;
   resurgence; rise.

encroachment.  1. The landward
   advancement of saline waters into coastal
   aquifers1161.  2. The displacement of clean
   water by pollutants[16].

end effect. A disturbance introduced by the
   inflow and outflow sections in a flow
   experiment[16].

endellite.  A cave mineral —
   Al2Si2O5(OH)4-2H2O[U].
 endogean.  Pertaining to the domain
   immediately beneath the ground surface,
   i.e., in the soil or plant litter[25]. See also
   endogenic, epigean, hypogearj.

 endogenic. 1. Pertaining to, or living in, the
   zone immediately beneath the earth's
   surface191. 2. Pertaining to geological
   process originating within the earth[16].
   See also endogean, epigean, hypogean.

 endokarst. The part of a vertically Ia3'ered
   karst system that is beneath the surface.
   Endokarst includes the full spbctram of
   underground voids and the dissolutional
   features that are present on the rock
   surfaces surrounding them[9]. ^ee also
   exokarst.                   :

 energy head. Hydraulic head plus velocity
   head'161.                    !

 enthalpy. Heat content[16].      \
                              \

 entrance capacity. The property of a soil to
   allow water to infiltrate (the maximum
   value of this property)1161.     '

 entrenchment. Erosion of an existing cave
   floor by a freely flowing stream to form a
   canyon passage that is commojnly
   narrower than the original passage.
   Where the stream entrenches kn
   originally tubular phreatic passage a
   characteristic keyhole shaped profile
   develops. Also known as  vadpse
   entrenchment or incision[9].   •

entropy. The degree of thermodynamic
   disorder[16].                 .

environment. All the external conditions
   surrounding a living thing[23].  ;
                                            68

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eolian calcarenite.  A terrestrial limestone
   formed by the cementation by carbonates
   of calcareous coastal dune sand. Often
   shorted to eolianite.  Synonym:
   dune-limestone; aeolianite.  Compare
   beachrock.

eolian deposit. Sediment material deposited
   bywindaction[16].

ephemeral stream. A stream  flowing only
   in direct response to precipitation[16].

epigean. Pertaining to, or living on, the
   surface of the earth. See endogean and
   hypogean.

epigeum. The surface environment1231.

epikarst; epikarst zone. A relatively thick
   (the thickness may vary significantly, but
   15 to 30 meters thick is a good
   generalization) portion of bedrock that
   extends from the base of the soil zone and
   is characterized by extreme fracturing and
   enhanced solution. It is separated from
   the phreatic zone by an inactive, relatively
   waterless interval of bedrock that is
   locally breached by vadose  percolation.
   Significant water storage and transport
   are known to occur in this zone.
   Synonym for subcutaneous zone.

 epikarstic flow.  See subcutaneous flow.

 epilimmion. Upper layer of stratified
'   water1"1.

 epiphreas, epiphreatic zone.  The zone in a
   cave system, immediately above the
   phreatic zone, affected morphologically
   and hydrologically by floods too large for
   the cave to absorb at once[10].
epsomite. A cave mineral —
  MgSO4-7H2O[11].

equation of hydrologic equilibrium. A
  mass balance for a ground-water basin[16].

equipotential line or surface. 1. A contour
  line on the potentiometric surface along
  which the pressure head of ground water
  in the aquifer is the same. Fluid flow is
  normal to these lines in the direction of
  decreasing fluid potential163. 2. Line (or
  surface) along which the potential is
  constant[22].

equivalent per million.  The number of
  equivalent weights in a million parts per
  weight solution116].

erodible. Susceptible to erosion[16].

erosion. 1. The general process or group of
  processes whereby the materials of the
  Earth's crust are moved from one place to
   another by running water (including
   rainfall), waves and currents,  glacier ice,
   or wind[6].  2. The sequence of processes
   of disintegration and transportation of
   rock material1161.

erosion surface. The land surface resulting
   from the action of erosion[16].

erosiveness.  The capacity to erode[161.

escarpment.  A steep slope, often the result
   offaulting[16].

 estavelle.  (French.) An intermittent
   resurgence or exsurgence, active only in
   wet seasons. May act alternatively as a
   swallow hole and as a rising according to
   ground-water conditions1101. Opening in
                                              69

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   karstic terrane which acts as a discharge
   spring 'during high potentiometric surface
   and as a swallet during low
   potentiometric surface. Sea estavelles are
   known to exist[20]. Synonyms: (French.)
   estavelle; (German.) Estavelle; (Greek.)
   estavella; (Italian.) estavella; (Russian.)
   estavella; (Spanish.) estavela; (Turkish.)
   sn batar fikan; (Yugoslavian.) estavela,
   ponor-rigalo.

esker. A stratified fluvio-glacial deposit in
   the form of a winding ridge[16].

etched pothole. See solution pan.

estuary. The lower course of a river
   discharging into the sea and subject to
   tidal currents1161.

evaporate. A sedimentary rock formed by
   evaporation and precipitation of saline
   waters1'61.

evaporation. The changing or water from
   the liquid or solid states into the gaseous
   state through heat exchange[16].

evaporation loss.  The loss of precipitated
   water that is  discharged to the atmosphere
   by evaporation1'61.

evaporation opportunity.  The amount of
   water made available for discharge into
   the atmosphere^161.

evaporation pan.  An open tank used to
   measure evaporation1161.

evaporation reduction. The rate control of
   escape of water vapor from an open
   surfacetl6].
evaporation suppression. The pomplete
   prevention of evaporation by mechanical
   or physico-chemical means (e.g.,
   monomolecular layer)[16].    ;

evaporite. Rock formed by precipitation of
   minerals from evaporating waiter, usually
   from sea water.  As sea water [evaporates
   the least soluble mineral contents
   precipitate first; these include ,calcium
   carbonate that is deposited as fine-grained
   limestone. If evaporation continues, first
   gypsum, then halite and finally a number
   of other sulfates and chlorides are
   deposited191.                 ,

evaporativity.  Evaporative power1'61.

evapotranspiration. 1. The combined loss
   of water from a given area an4 during a
   specified period of time, by evaporation
   from the land and transpiration from
   plants1221. 2. The return of water in vapor
   form to the atmosphere through the
   combined actions of evaporation, plant
   transpiration, and sublimation','61.
                              I
evolution.  The process of natural
   consecutive modification in the inherited
   makeup of living things; the process, by
   which modern plants and animals have
   arisen from forms that lived in the past[23].
   See also mutation.           •

evorsion. Mechanical erosion by whirling
   water that may carry sand and gravel;
   pothole erosion1-101. Mechanical erosion
   by rotating or whirling water carrying
   sand, gravel, cobbles, or boulders in
   suspension or as bedload[201. Synonyms:
   (French.) evorsion; (German.) I
   (Auswaschung), Auskolkung; (Greek.)
   mihanihi didvrosis; (Italian.) evorsione;
                                            70

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  (Spanish.) evorsion; (Turkish.) dev kazani
  a§mdirmasi; (Yugoslavian.) vrtlozna ,
  erozija.

exchange capacity. 1. The amount of
  exchangeable ions measured in moles of
  ion change per kilogram of solid material
  at a given pH. Synonymous with ion
  exchange capacity^21. 2. The total ionic
  charge of the adsorption complex active
  in the adsorption of ions[22]. See also
  cation-exchange capacity.

exhumed karst. A karstic outcrop which
  has been exposed by the erosion of an
  allochthonous cover; there is an
  implication that karstification (partial or
  complete) had preceded the removal of
  the cover[20]. Mantled karst or buried
  karst which has been divested of its
  cover. It is the re-exposed portion of a
  former landscape1"1.  See also buried
  karst; exposed karst; mantled karst.
   Synonyms: (French.) karst denude;
   (German.) wiederaufgedeckter Karst;
   (Greek.) gymnothen karst; (Italian.) carso
   riesumato; (Spanish.) karst exhumado;
   (Turkish.) acik karst; (Yugoslavian.)
   ogoljeli krs (kras).

 exogenic.  Pertaining to processes on or near
   the surface of the earth[16].

 exokarst.  All features that may be found on
   a surface karst landscape, ranging in size
   between tiny karren forms and extensive
   projes, belong to the exokarst[9]. See also
   endokarst.

 exoskeleton.  An external skeleton. The
   hard body covering or shell of most
   invertebrate animals, including insects,
   crayfish, and millipedes[23].
experimental basin. A basin chosen for the
  thorough study of hydrological
  phenorriena[16].

exposed karst. A general term for bare
  karstic rocks outcropping at the surface of
  the ground. It embraces karst areas
  without any initial cover (naked karst) or
  exposed by erosion of the residuum and
  soil (denuded karst) or of the
  allochthonous cover (exhumed karst)[20].
  Karst topography in which cover is
  absent[17].  Synonyms: (French.) karst
  expose; (German.) nackter Karst,
  oberfldchlicher Karst, wiederaufgedeckter
  Karst; (Greek.) akalypton karst; (Italian.)
  carso denudato;  (Russian.) golij karst,
  otkritij karst; (Spanish.) karst subaero;
   (Turkish.) belirgin karst; (Yugoslavian.)
   ljuti krs.  See also denuded karst;
   exhumed karst; naked karst.

 extensometer. An instrument used for
   measuring vertical deformation of fine-
   grained beds in the subsoil under stress.
   Vertical extensometers commonly are
   installed when land subsidence follows
   ground-water withdrawal.  Extensometers
   also are used to measure small horizontal
   displacements1211.

 external  loads. External loads causing
   water level fluctuations in wells.

 exsurgence. 1. A term used to explain the
   re-emergence at the surface, as a stream,
   of meteoric water which has fallen
   entirely upon and percolated through a
   calcareous massif1191. 2. A spring or seep
   in karstic terrane not clearly connected
   with swallets a higher level. Synonyms:
   (French.) exsurgence; (German.)
   Karstquelle, Austrittfitelle; (Greek.)
                                             71

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karstikipighi; (Italian.) risorgente
carsica; (Russian.) karstovij istocnik;
(Spanish.) exsurgencia; (Turkish.)
yuzeyde blirme; (Yugoslavian.) vrelo,
obrh. See also emergence; resurgence.
                                           72

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fabric. The orientation in space of the
   elements composing a rock substance.

facet. See scallop.

facies. The lithologic appearance of a
facies change.  The change in appearance
   that occurs when one lithologic unit ends
   and a new one is encountered.

failure. In rocks, failure means exceeding
   of the maximum strength of a rock or
   exceeding the stress or strain requirement
   of a specific design.

fall. The gross slope of a river[16].

false floor.  A remnant of a sheet of
   flowstone, originally deposited on clastic
   sediments that were subsequently washed
   out from beneath. False floors may
   survive as a complete bridge between
   passage walls or just as projecting ledges.
   They may be thin and easily broken or
   thick and very strong191.

farangothes ipoyios thiavasis. See aisle.

fathometer. A water depth measuring
   device[I6].

fault. 1 . A fracture in the earth's crust,
   across which relative rock movement has
   taken place, or continues to take place.
   Fault planes commonly guide vertical or
   sub-vertical shafts in caves, as well as
   guiding sub-horizontal or oblique
   passages within the confines of the fault
   plane[9].  2. A fracture or fracture zone
  along which there has been displacement
  of the two sides relative to one another
  parallel to the fracture[6]. This
  displacement maybe of a few centimeters
  or many kilometers.  See also joint fault
  set; joint fault system.

fault breccia.  The assemblage of broken
  rock fragments frequently found along
  faults. The fragments may vary in size
  from inches to feet.

fault cave. A cave developed along a fault
  or fault zone[10].

fault gouge. A clay-like material occurring
  between the walls of a fault as a result of
  the movement along the fault surfaces.

fault line.  The intersection of a fault with
  the surface of the earth or any other plane
  of reference^161.

fault plane. A plane on which  dislocation
   and relative movement has taken place[16].

fault scarp. An elevation formed by
   movement of blocks along a  fault
   plane[16].

fault zone. A zone with numerous small
   parallel faults[16].

feeding tube, hi karst terrane, a more or
   less straight and waterbearing
   underground gallery of regular cross-
   section. Synonyms: (French.) tunnel;
   (German.) Stromungsrohr, Karstgerinne;
   (Greek.) karstikos ypoyios agogos;
   (Spanish.) tubo; (Turkish.) akarsu
   mecrasi; (Yugoslavian.) vodonosni rov.
   See also stream tube.
                                             73

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 feldspars. A very common group of rock
   forming minerals[16].

 fengcong; fengcong karst. (Chinese.)  LA
   karst, conspicuous in China, that is
   identified by its clustered limestone hills.
   Fengcong (pronounced 'fungston'), which
   translates as 'peak cluster', is a mature
   karst normally developed during long
   uninterrupted periods of rapid dissolution
   in wet tropical environments with high
   levels of biogenic soil carbon dioxide.
   The Chinese classify karst by the hill or
   peak density, in contrast to the Western
   classification by hill shape. Fencong is
   almost the equivalent of cone karst; its
   closely packed hills are conical rather
   than hemispherical, with intervening
   dolines and disjointed valleys. The major
   occurrences  are in Guizhou and Guangxi,
   in southern China.  Some cones in
   Guangxi are so steep that they have been
   termed fengcong tower karst, but this
   concept is best avoided[9].  2. Tower karst
   characterized as peak cluster because the
   individual karst towers appear to be
   grouped together in clusters.  Closed
   depression among the peaks are
   common[43.  See also fenglin; fungling;
   mogote; tower karst.

fenglin; fenglin karst. (Chinese.) 1. A
   karst, conspicuous in China, that is
   identified by its isolated limestone hills.
   Fenglin (pronounced 'funglin') translates
   from Chinese as 'peak forest', and is
   distinguished from fengcong.  Both
   fenglin and fengcong are mature karst
   normally only developed by long
   uninterrupted periods of rapid dissolution
   in wet tropical environments with high
   levels of biogenic soil carbon dioxide.
   The Chinese classify karst by the hill or
   peak density, in contrast to the Western
   classification by hill shape. Fenglin is
   therefore almost the equivalent of tower
   karst; its hills have very steep or vertical
   walls, and may have a height/width ratio
   greater than four.  The limestone hills rise
   above level, alluviated plains, and the
   finest fenglin karst around Yangshuo,
   Guangxi, in southern China, is one of the
   world's most dramatic landscapes. The
   classification by hill density means that
   low residual cones scattered across a plain
   are also referred to as fenglin by the
   Chinese191.  2. Tower karst characterized
   as peak forest because the individual
   towers appear as isolated  groups on a
   plain. Dry valley networks separate
   individual towers[4]. See also fengcong;
   fungling; mogote; tower karst.

ferghanite. A cave mineral	[
   U3(V04)2-6H2O[1I].

ferric oxide. Rust; hematite (Fe2O3)[16].

ferrito zone. Zone of iron oxide
   accumulation in soil under humid climate
   conditions[16].

Fickian diffusion. The spreading of solutes
   from regions of highest to regions of
   lower concentrations caused by the
   concentration gradient.  In slow moving
   ground water, this is the dominant mixing
   process[22].                  \

fissure. Any discontinuity within the rock
   mass that is either initially opeii or
   capable of being opened by dissolution to
   provide a route for water movement.
   Fissures in this sense, applied generally in
   karst, therefore include the primary
   sedimentary bedding planes as1 well as
                                            74

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  tectonic faults and joints. More
  specifically, the term has been used to ^,
  describe voids with average dimensions
  from 10 to 100mm[9]. See also conduit;
  fracture.

field capacity; field moisture capacity.
  See specific retention.

field survey. Measurements taken in the
  field[16].

field test. A test run in the field under
  normal field conditions1161.

field velocity of ground water.  Actual
  interstitial velocity of ground water[I6].

fill terrace.  An elevated valley surface
  formed by aggregation1161.

fine gravel. Rock aggregates of 1-2 mm
  diameter[16].

fine sand. A silicon dioxide material with a
  grain diameter of 0.1- 0.25 mm1161.

finite difference method.  A numerical
  method used to approximate the solution
  of partial differential equations1161.

finite element method. A numerical
  method used to approximate the solution
   of partial differential equations.

firn.  Compacted granular snow[161.

firstkarren. (Austrian.) See Rillenkarren.

fissure. An open joint or crack in rocks[16].

fissure cave. A narrow vertical cave or cave
   passage along a fissure.  Fissures widen
  out to become wells or vertical shafts[10].
  Se.e ajso vertical shaft.

Flachkarren. (German.) See clint.

flank. A limb of a fold1161.

flash flood. A relatively short but very
  intense flood[16].

flattener. A cave passage, which though
  wide, is so low that movement is only
  possible in a prone position'101. See also
  crawl.

flexure. A bend in a stratum with one flank
  or limb only1161.

flint. A concretionary form of silica, similar
  to chert, that occurs in chalk as tabular
  sheets and layers of irregularly shaped
  nodules.  Being very hard and relatively
  insoluble, flint tends to stand out from
  chalk cliffs. Flint-rich horizons may also
  influencer the inception of bedding-
  related dissoluational conduits in chalk[9].

float gage.  A device that indicates or
  records water levels with a float[16].

floating pan. An evaporation pan floating
   in a water body with drum floats1161.

floe calcite.  Very thin film of pure calcium
   carbonate floating on the surface of a
   subterranean pool of very calm water1101.

flood. A high river flow overtopping banks.

flood crest.  The peak of a flood wave[16].

flooding method. A recharge method by
   flooding a recharge area[16].
                                             75

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floodmarks. The marks left on fixed
   objects by flood waters[I6].

flood plain. The surface or strip of
   relatively smooth land adjacent to a river
   channel, constructed by the present river
   and covered with water when the river
   overflows its banks. It is built of
   alluvium carried by the river during
   floods and deposited in the sluggish water
   beyond the influence of the swiftest
   current161.

flood profile.  A continuous line
   representing the water surface for a given
   rateofflow[16].

flood water. Water that has overflowed its
   confines; the water of a flood[I].

flood-water zone.  See epiphreas.

flood wave. A rise in the stage of a stream
   that culminates in a crest before
   receding^3.

floor pocket. See pocket.

flow, base. See base flow.

flow, creep. Flow with a creeping motion
   where inertial terms have been
   dropped1161.

flow, critical.  See critical flow.

flow duration curve.  A curve of
   cumulative streamflow versus the
   corresponding per cent of time[16].

flow gage.  A gage used to measure flow
   ratet161.  See also gage.
flow-mass curve.  1. A mass curve with
   runoff discharge as ahydrologic
   quantity1161. 2. The integral of the curve
   ofahydrograph[16].         j

flow line. The general path that|a particle of
   water follows under laminar flow
   conditions1221. Flow lines are usually
   drawn perpendicular to equipotential
   lines.  See also equipotential lines.

flow net.  1. A graphical representation of
   flow lines and equipotential lilies for
   two-dimensional, steady-state
   ground-water flow[22]. 2. A net of
   orthogonal streamlines and equipotential
   lines applied in the graphical solution of
   Laplace's equation[16].       '

flow path. The subsurface course a water
   molecule or solute would follow in a
   given ground-water velocity field.

flow rate. Volumetric rate of fl6w[161.
                             i
flow, steady. A characteristic of a flow
   system where the magnitude and direction
   of specific discharge are constant in time
   at any point[22]. See also flow, unsteady.
                             i
flow, uniform. A characteristic iof a flow
   system where specific discharge has the
   same magnitude  and direction at any
   point"?2'.                   |
                             j
flow, unsteady. A characteristic of a flow
   system where the magnitude and/or
   direction of the specific discharge
   changes with time. Synonymous with
   nonsteady flow.  See also flow, steady.

flow velocity. See specific discharge.
                                           76

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flower. A cave flower is a group of crystals,
   commonly of gypsum or mirabilite, that
   grow by accretion at their bases on a cave
   wall. As the crystals grow, curve and
   splay, their form mimics that of a
   flower[9].

flowing artesian well. A well with its
   potentiometric surface above the ground
   surface'161.

flowmeter. An instrument for measuring
   volumetric flowrate[161.

flowstone. Deposits of calcium carbonate,
   gypsum, and other mineral matter which
   have accumulated on the walls or floors
   of caves at places where water trickles or
   flows over the rock[10].  Layered deposits
   of calcium carbonate precipitated on
   rocks from water trickling over them[201.
   (French.) coulee stalagmitique;
   (German.) Sinterfall, Sinter, (Greek.)
   asvestolithikon epiphlioma; (Italian.)
   colata stalagmitica, deposito,
   concrezione, stalagmite; (Russian.)
   nateki;  (Spanish.) colada estalagmitica;
   (Turkish.) akmata^.; (Yugoslavian.)
   kaskade.  See also dripstone.

 fluid potential. The mechanical energy per
   unit mass of a fluid at any given point in
   space and time with regard to an arbitrary
   state and datum[22].

 fluorapatite.  A cave mineral —
   Ca5(P04)3F[ni.

 fluorite.  A cave mineral — CaF2[11].

 flume.  A channel supported on or above
    ground[16].
fluorescein. A reddish-yellow crystalline
  compound that imparts a brilliant green
  fluorescent color to water in very dilute
  solutions; used to label underground
  water for identification of an
  emergence1101. Also commonly known as
  uranine. Dye type: Xanthene.

fluorescent dyes.  Material used in
  environmental tracing studies that may be
  detected and measured in small
  concentrations (~10~12 mg/L), are
  inexpensive, relatively nontoxic, and are
  relatively miscible with the water being
  traced.

fluorometer, filter fluorometer.  A highly
   sensitive instrument used for measuring
   the fluorescence of water.  It is commonly
   used in water tracing and tracer gaging.
   Selected filters are used to control the
   excitation and emission ranges for
   specific fluorescent dyes of interest.  See
   also scanning spectrofluorophotometer.

 flushed zone,  hi geophysical well logging,
   the zone around the well bore completely
   invaded by the mud filtrate[16].

 flute. See scallop.

 fluviokarst. 1. A karst landscape where the
   dominant landforms are valleys cut by
   surface rivers.  Such original surface flow
   may relate either to low initial
   permeability before caves (and hence
   underground drains) had developed, or to
   reduced permeability due to ground
   freezing in a periglacial environment. In
   both cases the valleys become dry as karst
   development improves underground
   drainage191.  2.  Mixed terranes
   characterized by both shallow karst and
                                              77

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   erosional landscape[20]. 3.  A
   predominantly karst landscape in which
   there is much evidence of past or present
   fluvial activity1101. Synonyms:'(French.)
   fluviokarst; (German.) Fluviokarst;
   (Giesk.') fluviokarst; (Italian.)
   fluviocarsimo; (Spanish.) fluviokarst;
   (Turkish.) akarsu karsti: (Yugoslavian.)
   fluviokrs, fluviokras, fluviokarst.

flux. See specific discharge.

foaming agent. See surfactant.

foiba. (Italian.) 1. A deep wide vertical
   cavity or the swallow point of a river at
   the beginning of its underground course.
   2. A natural vertical shaft in soluble rock,
   tending toward cylindrical shape; it may
   or may not reach the surface. A dome
   pit'101.

fold. A bend in a geologic stratum with two
   flanks, often in anticlinal and synclinal
   sequence.

food chain.  A series of plants and animals
   linked by their food relationships; the
   passage of energy and materials from
   producer through a succession of
   consumers. Green plants, plant- eating
   insects, and an insect-eating bat would
   form a simple food chain[23]. See also
  food web.

food pyramid.  The normally diminishing
   number of individuals and amount of
   organic material produced at each
   successive level along a food chain. The
   declining productivity at each level
   results from the constant loss of energy in
   metabolism as the energy passes along the
   chain1231. See also trophic level.
 food web. An interlocking system of food
   chains.  Since few animals rely on a
   single food source and since no food
   source is consumed exclusively by a
   single species of animal, the separate food
   chains in any natural community interlock
   and form a web[23].          ;

 forestry compass. A lightweight, compact
   instrument to be mounted on a tripod,
   which functions as  a compass  and a
   clinometer, and has a telescopic sight.
   Some types facilitate measurement of
   horizontal angles as well as bearings[25].

 formation. The fundamental uriit in
   rock-stratigraphic classification,
   consisting of a distinctive mappable body
   of rock[10]. See also cave formation;
   speleothem.                i

 formation temperature. The prevailing
   temperature in a given subsurface
   fbrmation[I6].               ;

 formation stabilizer.  A sand or  gravel
   placed in the annulus of the well between
   the borehole wall and the well  screen to
   provide temporary or long-term support
   for the borehole[6].          ,

 form factor. A factor indicating  the shape
   and form of mineral aggregates
   influencing their hydrodynamic
   properties[16].

fossil. Any remains or traces of animals or
   plants that lived in the prehistoric past,
   whether bone, cast,  track, imprint, pollen,
   or any other evidence of their',
   existence[23].
                                            78

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fossil cave.  A fossil cave is an underground
   cavity that formed when a carbonate  •-,-.,
   succession was undegoing karstification
   but subsequently buried. Most fossil
   caves have been infilled by younger
   sediments.  See neptunian deposits,
   palaeokarst, and relict cave.

fossil karst. See paleokarst.

fossile karst.  (French.) See buried karst.

fouling. The process in which undesirable
   foreign matter accumulates  in a bed of
   filter media or ion exchanger, clogging
   pores and coating surfaces and thus
   inhibiting or retarding the proper
   operation of the bedt6].

fountain. A free-flowing well or spring[16].
   See also artesian well; spring, artesian.

fracture. 1. A break or secondary
   discontinuity in the rock mass, whether or
   not there has been relative movement
   across it. Faults, thrusts, and joints are all
   fractures, but bedding planes, which are
   primary features, are not. In a more
   strictly hydrogeological context the term
   has been used to classify voids in the size
   range 0.1 to 10mm[9].  2. Breakage of rock
   strata[16].  3. The general term for any
   mechanical discontinuity in the rock; it is,
   therefore, the collective term for joints,
   faults, cracks, etc. See also conduit;
   fissure.

fracture pattern. The spacial arrangement
   of a group of fracture surfaces.

fracture spring.  See spring, fracture.
fracturing.  A formation of breaks in a rock
  due to folding or faulting[I6].

francoanellite. A cave mineral —
  H6K3Al5(P04)8-13H2Otnl.

free pitch. Where a rope or ladder hangs
  vertically and free of the walls[251.

free-surface stream,  hi a cave, a stream
  that does not completely fill its
  passage[10].

free water.  See gravitational water.

free-water elevation.  See water table.

freezing point. The point at which a liquid
  solidifies[16].

fresco.  A half-section of a stalactite  on the
  wall of a cave.

fresh water. Water that contains less than
  1,000 milligrams per liter (mg/L) of
  dissolved solids; generally more than 500
  mg/L is undesirable for drinking and
  many industrial uses[22].

freshwater lens. 1. Body of fresh ground
  water found typically beneath permeable
  limestone islands or peninsular land
  masses in the tropics.  The lens-shaped
  water body is bounded above by a water
  table and below by a mixing zone
  between fresh and saline ground water
  along the halocline. hi the center of the
  lens freshwater extends below sea-level,
  and another set of springs exists where
  dissolutional conduits associated with the
  lower limit of the lens intersect the rock
  surface below sea-level[9]. 2. A lenticular
                                             79

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   form of a freshwater body under oceanic
   coasts[161.

friction head. Head loss due to energy
   dissipation by friction1161.

friend.  A mechanical camming device used
   for anchors1251.

Froude number. A dimensionless
   numerical quantity used as an index to
   characterize the type of flow in a
   hydraulic structure that has the force of
   gravity (as the only force producing
   motion) in conjunction with the resisting
   force of inertia. It is the ratio of inertia
   forces to gravity forces, and is equal to
   the square of a characteristic velocity
   (mean, surface, or maximum velocity) of
   the system divided by the product of a
   characteristic linear dimension (e.g.
   diameter or depth) and the gravity
   constant, acceleration due to gravity, all
   of which are expressed in consistent units
   in order that the combinations will be
   dimensionless. The number is used in
   open-channel flow studies or where the
   free surface plays an essential role in
   influencing motion^11 such as in karst
   conduits that are not necessarily flowing
   at pipe-full conditions. See also Chezy
   equation; Manning equation; Reynolds
   number.

fullflow spring. See spring, fullflow.

fungling; fungling karst. (Chinese.)
   Isolated limestone hill in alluvial plain,
   probably similar to mogote[10]. See also
   fencong; fenglin; mogote; tower karst.
funicular regime.  The distribution of
  continuous liquid phase along pore walls
  with gaseous phase at the pore center1-161.
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gage well.  A stilling well in which stage
  measurements are performed1161.

gage station. The point at which stage
  measurements are performed1161.

gaining stream. A stream or reach of a
  stream whose flow is being increased by
  inflow of ground water[22].

galena. A cave mineral — PbS[11].

gallery.  A rather large, nearly horizontal
  passage in a cave[10].

galvanometer. A sensitive current meter[16].

gardening. Clearing stones or other loose
   material from a route, usually a pitch,
   which might otherwise be dangerous to a
   caver continuing1251.

gas-expansion method. The measurement
   of porosity based on the Boyle-Mariotte's
   gas laws[16].

geo. See blowhole.

geode. Hollow globular bodies varying in
   size from a few centimeters to several
   decimeters,  coated on the interior with
   crystals[10].

 geochemistry. The science of the
   qualitative and quantitative identification
   of the elements and their distribution in
   the earth[16].

 geodesy.  The science of measuring the
   geometrical properties of the earth[16].
geohydr"blogic system. The geohydrologic
  units within a geologic setting, including
  any recharge, discharge, interconnections
  between units, and any natural on
  man-induced processes or events that
  could affect ground-water flow within or
  among those units[22]. See also ground-
  water system.

geohydrologic unit. An aquifer, a,
  confining unit or a combination of
  aquifers and confining units comprising a
  framework for a reasonably distinct
  geohydrologic system[22].

geohydrology. The branch of hydrology
  relating to the quantitative treatment of
  ground-water occurrence and flow[16].

geological column. A vertical cross section
  through a sequence of formations1161.

geological map. A map on which is
   recorded geologic information, such as
   the distribution, nature, and age
   relationships of rock units (surficial
   deposits may or may not be mapped
   separately), and the occurrence of
   structural features (folds,  faults, joints),
   mineral deposits, and fossil localities. It
   may indicate geologic structure by means
   of formational outcrop patterns, by
   conventional symbols giving the direction
   and amount of dip at certain points, or by
   structure-contour lines[11.

 geological organ. A cylindrical or funnel-
   shaped cavity in relatively soluble
   bedrock which typically has a vertical
   orientation and is partly or wholly filled
   with material similar to the overlying
   sediment cover.  They are produced by
   solution of bedrock and concomitant
                                             81

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   subsidence of its sedimentary cover.
   Most have a diameter of 25 cm to 7 m
   and a depth of 2 to 30 m, but some may
   be much larger. A depth/diameter ratio of
   5 to 20 may be considered representative.
   In actuality, geological organs are a type
   of subsidence doline that develops under
   a cover of younger rock or sediment[17].
   Synonyms: (French.) Orgue geologigue,
   poche de dissolution, puits naturel;
   (Belgian.) abannet, cavite de dissolution;
   (German.) geologische Orgel, Orgel,
   unterirdische Doline,  Verwitterungssacke,
   naturlicher Schacht, Erdorgel, Erdpfeife,
   Riesentoph, Bodenkarren, (British.) sand
   pipe, sand-gall, gravel-pipe, pipe, pocket
   deposit, gull; (Italian.) organo geologico;
   (Roumanian.) orgile geologice; (Czech.)
   geologicke varhany; (Polish.) organy
   geologiczne; (Russian.) organ truba,
   kamin; (Serbo-Croatian.) geoloske
   orgulje; (Slavic) geoloske orglje, zapolvje
  jaski; (Dutch.) geologische orgelpijp,
   aardpijp.

geological section. A vertical section
   through a sequence of rock masses or
   strata[16].

geologic control. The influence of geologic
   factors on  hydrogeologic features[16].

geologic correlation. The correlation of
   geologic formations as shown in geologic
   logs over a given area[16].

geologic hazard. A naturally occurring or
   man-made geologic condition or
   phenomenon that presents a risk or is a
   potential danger to life and property.
   Examples include landsliding, flooding,
   earthquakes, ground subsidence, coastal
   and beach  erosion, faulting, dam leakage
   and failure, mining disasters, pollution
   and waste disposal, and seawater
   intrusion[1].                 [
                              i
 geologic log. A vertical cross section of the
   lithologic column indicating geologic and
   petrographic data[16].         <

 geologic similarity. A model-prototype
   length ratio[16].

 geology. The study of the planet Earth—the
   materials of which it is made, [the
   processes that act on these materials, the
   products formed, and the history of the
   planet and its life forms since its origin.
   Geology considers the physical forces that
   act on the Earth, the chemistry of its
   constituent materials, and the biology of
   its past inhabitants as revealed by fossils.
   Clues on the origin of the planet are
   sought in a study of the Moon: and other
   extraterrestrial bodies.  The knowledge
   thus obtained is placed in the service of
   man—to aid in discovery of minerals and
   fuels of value in the Earth's crust, to
   identify geologically stable sites for major
   structures, and to provide foreknowledge
   of some of the dangers associated with
   the mobile forces of a dynamic Earth[1].

geomorphic process. The process
   responsible for the  formation and
   alteration of the earth's surface[I6].

geomorphology. The science ofthe origin
   and evolution of land forms[I6]j

gestation.  The gestation phase of
   speleogenesis follows the inception
   phase, and the two in combination are
   essentially equivalent to the more
   commonly used  term'initiation'. The
                                             82

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  transition from inception to gestation may
  correspond to the establishment of
  gravitational laminar flow conditions, and
  gestation is complete when turbulent flow
  is achieved191.

Ghyben-Herzberg conditions. Equilibrium
  condition at the interface of immiscible
  freshwater bodies and saltwater bodies in
  coastal aquifers[16].

gibbs. An ascender with its cam operated
  by the weight of the caver[25].

glacial deposit. Sedimentary deposits due
  to transport by glaciers[16].

glacial drift. Sediment material contained,
  transported, and deposited by glaciers[16].

glacial groove. A groove cut into bedrock
  by rock fragments at the bottom of a
  moving glacier[16].

glacial till. An unassorted mixture of
  glacial drift[16]. Synonym: boulder clay;
  till.

glaciation. A covering of the land surface
  by glacier ice[16].

glacier.  An extensive body of ice covering
  the land surface[16].

glacier cave. 1. A cave carved out of the ice
  inside a glacier, not to be confused with
  an ice cave.  Passages are formed by
  meltwater descending from the glacier
  surface via crevasses, or by melting on
  the glacier base. Through caves may
  connect sinkholes (sometimes called
  moulins) to glacier snout resurgences, but
  due to ice movement most glacier caves
  are ephemeral. The most extensively
  explored glacier caves were the Paradise
  Caves on Mount Rainier, USA, whose
  passages extended for many kilometers,
  before the glacier wasted away and the
  caves were destroyed[9].  2. Cave in ice
  formed within or at the base of a
  glacier[10].

glaciofluvial.  Pertaining to the meltwater
  streams flowing from wasting glacier ice
  and especially to the deposits and
  landforms produced by such streams[6].

glaciokarst.  1. A karst landscape that was
  glaciated during the cold periods of the
  Pleistocene and displays major landforms
  of relict glacial origin. Bare rock scars,
  locally with glacial striations, and
  limestone pavements are characteristic,
  due to the lack of rapid soil formation on
  the limestones since glacial stripping.
  Dolines within a glaciokarst are mostly
  small and immature, as are caves, except
  where pre-glacial passages are
  intercepted.  Glaciokarst is almost
  synonymous with alpine karst, and some
  of the finest is developed on the high
  plateaus of the Calcareous Alps, south of
  Salzburg, Austria[9].  2. A glaciated
  limestone region possessing both glacial
  and karst characteristics1101. (French.)
  karst glaciaire;  (German.) Gebiet mil
  karst und Glazial-Formen; (Greek.)
  pagheto-karst; (Spanish.) glaciokarst;
  (Turkish.) buzul karsti; (Yugoslavian.)
  glaciokrs glaciokras, glaciokarst. See
  also alpine karst; nival karst.

glade. 1. (Jamaican.) An elongate
  depression, having steep sides, in which a
  generally flat floor is divided into small
  basins separated by low divides.  2.
                                             83

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   (Tennessee.) Limestone pavement having
   extensive growth of cedar trees[IO].  See
   also uvala.

globularite. Small crystals of calcite tipped
   with spheres composed of radiating
   fibers1101.

gloop. Synonym for blow hole. Also
   spelled gloup.

goethite.  A cave mineral — FeO(OH)[n].

golyikarst. (Russian.) See naked karst.

gooseneck.  The part of a winding valley
   resembling in plan the curved neck of a
   goose.  Normally found as part of an
   entrenched meanderm.

gorge. A narrow passage or canyon in a
   mountain system'161. See also canyon.

gour. Flowstone deposit, normally of
   calcite, built up along the edge of a pool
   due to precipitation from a thin film of
   overflow water.  Once initiated, by
   calcite-sarurated water overflowing from
   floor hollows, development is self-
   enhancing, and the gours can grow into
   large dams many meters high and wide.
   Inside the gour pool, more calcite may be
   precipitated as crystals or pearls. Large
   flights of gours occur in many caves, with
   spectacular and well known examples
   around the Hall of Thirteen in the Gouffre
   Berger, France. Large travertine, gours
   can form in the open air, as at Band-i-
   Amir, Afghanistan191.  See also rimstone
   barrage; rimstone barrier; rimstone dam.
graben.  A depression formed by a fault
   block moving downward on the two
   bounding faults'161.           |

gradation. The leveling of a surface to a
   common level[16].            j
                              I
grade. 1. Inclination or slope[16]; 2. The
   class of a cave survey on the basis of the
   precision of the instruments and the
   accuracy of the methods[25].   i

graded.  An engineering term pertaining to a
   soil or an unconsolidated sediment
   consisting of particles of several or many
   sizes or having a uniform or equable
   distribution of particles from coarse to
   fine!61.                      '
                              i
gradient. The change in hydraulic head
   over some given distance (dh/dL) with
   ground-water flow usually occurring in
   the direction of decreasing hydraulic head
   which requires by convention, the
   attaching of a minus sign to any equation
   utilizing a gradient for flow. The
   maximum value of the directional
   derivative'161.                ;
                              [
                              i
grain packing. The spatial arrangement of
   grains  forming porous medium1-161.

grain per. gallon (gpg.) A common basis for
   reporting water analyses in the water-
   treatment industry in the United States
   and Canada.  One grain per UJS. gallon
   equals 17.12 milligrams per liter[6].

grain shape.  The geometrical aspect of
   grains1161.                    •

granular. Of structure clearly showing
   grain shape[16].               !
                                            84

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granule. Small rounded grain or rock
   fragment1161.                         *

grape formation.  See botryoid.

gravel.  Waterworn rounded rock grains and
   fragments'161.

gravimetric moisture content. The ratio of
   water weight to the weight of solid
   particles[16].

gravitational head. The component of total
   hydraulic head related to the position of a
   given mass of water relative to an
   arbitrary datum[22].

gravitational water. Water which moves
   into, through, or out of the soil or rock
   mass under the influence of gravity1221.

gravity component.  The component acting
   in the direction of gravitation1161.

gravity drainage. The flow of water
   towards a well under its own weight[16].

 gravity spring. See spring, gravity.

 grid north.  The direction of a north-south
   grid line on a map. Except for the
   north-south grid line through  the point of
   origin of the grid, it will differ slightly
   from true north[25].

 grike.  (British.)  1. A solutionally enlarged
   vertical or steeply inclined joint in the
   surface of a karstland, extending for up to
   a few meters into the limestone[1°!. 2. A
   vertical or sub-vertical cleft in a
   limestone pavement developed by
    solution along a joint or system of
    crisscrossing joints'201. Grikes separate
  clints from one another. Synonyms:
  (British.) gryke; (French.) lapiaz;
  (German.) Kluftkarren.  See also clint;
  bogaz; limestone pavement.

grotto.  1. Hole in small cave or cavern
  which has eroded in the wall of a main
  cave. 2. Widely open and shallow cave
  within a vaulted roof. 3. A cave or
  chamber preceded by a narrower
  passage1201.  4. A small cave, natural or
  artificial.  5. A room, in a cave system, of
  moderate dimensions but richly
  decorated1101. A grotto is often intricately
  decorated, and may occur above, at, or
  below sea-level[20]. Synonyms: (French.)
  grotte, bourne, balme; (German.) Hohle,
   Grotte; (Greek.) spelean; (Italian.) grotta;
   (Russian.) grot; (Spanish.) grata;
   (Turkish.) magarauk; (Yugoslavian.) nis
 ground air.  See soil air.

 ground slope. The inclination of the land
   surface with the horizontal'161.

 ground water, phreatic water.  1 . The part
   of the subsurface water that is in the
   phreatic zone[10]. Its lower limits are the
   zone of rock flowage or the lowest fully
   confining bed; its upper limits are the
   uppermost fully confining bed or the
   water table[16]. 2. Used loosely and
   incorrectly by some to refer to any water
   beneath the surface. See also phreas;
   phreatic water; phreatic zone.

 ground-water artery. A tubular body of
   permeable water-filled material
   surrounded by confining beds[16].
                                              85

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ground-water barrier. Rock or artificial
  material which has a relatively low
  permeability and which occurs below the
  land surface where it impedes the
  movement of ground water and
  consequently causes a pronounced
  difference in the potentiometric surface
  on opposite sides of it[22].

ground-water basin. 1. A general term
  used to define a ground-water flow
  system that has defined boundaries and
  may include permeable materials that are
  capable of storing or furnishing a
  significant water supply; the basin
  includes both the surface area and the
  permeable materials beneath it[22]. 2. The
  area throughout which ground water
  drains towards the same point; it can be
  larger than the accompanying surface
  water drainage basin if permeable layers
  extend outside of the topographic
  divide'161.  See also drainage basin.

ground-water cascade. The flow of ground
  water over a subsurface barrier'161.

ground-water cement. A cementing
  material precipitating at the water
  table^.

ground water, confined.  Ground water
  under pressure significantly greater than
  atmospheric and whose upper limit is the
  bottom of a confining unit[22].  See also
  confined;  confining unit; confined
  aquifer.

ground-water dam. A geological stratum
  serving as a subsurface dam[16].

ground-water discharge.  1. Flow of water
  from the zone of saturation'221. 2. The
  water released from the zone of
  saturation[22].               \

ground-water divide. 1. A ridge in the
  water table or other potentiometric
  surface from which ground water moves
  away in both directions normal to the
  ridge line[22]. 2. A dividing line between
  two ground-water basins. 3. In well
  hydraulics, the streamline with no flow
  representing the boundary of the aquifer
  region contributing to well discharge'161.
  See also divide. Synonyms: divide;
  water-table divide.

ground-water flow. The movement of
  water in the zone of saturation'221.

ground-water flux.  The rate of
  ground-water flow per unit area of porous
  or fractured media measured j
  perpendicular to the direction jof flow'221.
  See also specific discharge.   I
                             i
ground-water inventory. The complete
  quantitative accounting for all, volumes of
  ground water'161.

ground-water mound.  A raised area in  a
  water table or other potentiometric
  surface created by ground-water
  recharge'221.

ground water, perched. Unconfined
  ground water separated from an
 . underlying body of ground water by an
  unsaturated zone.  Its water table is a
  perched water table. Perched ground
  water is held up by a perching bed v/hose
  permeability is so low that water
  percolating downward through it is not
  able to bring water in the underlying
  unsaturated zone above atmospheric
                                           86

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  pressure1221.  See also perched ground
  water.                             .:-,

ground-water pumping. 1. Directed or
  oscillatory ground-water movement,
  along incipient fissures in the rock, that
  occurs due to very small but significant
  relative movements of the rocks
  themselves, maybe as a diurnal, tidal
  process. It may be one of the driving
  mechanisms of earliest, inception, phase
  of speleogenesis[9]. The pumping of a
  water well to provide water for drinking,
  irrigation, and manufacturing, but may
  also be conducted for dewatering
  purposes.

ground-water recharge. The process of
  water addition to the saturated zone or the
  volume of water added by this process[22].

ground-water reservoir. A reservoir in the
   void space beneath the water table[16].

ground-water system.  A ground-water
   reservoir and its contained water. Also,
   the collective hydrodynamical and
   geochemical processes at work in the
   reservoir[22].

ground-water table. The surface between
   the zone of saturation and the zone of
   aeration. Also, the surface of an
   uncoiifmed aquifer[6].  Synonym: water
   table.

 ground-water travel time.  1. The
   time-required for ground water to travel
   between two locations[22]. 2. The time
   required for a unit volume of ground
   water to travel between two locations.
   The travel time is the length of the flow
   path divided by the velocity, where
  velocity is the average ground-water flux
  passing through the cross-sectional area
  of the geologic medium through which
  flow occurs, perpendicular to the flow
  direction, divided by the effective
  porosity along the flow path. If discrete
  segments of the flow path have different
  hydrologic properties, the total travel time
  will be the sum of the travel times for
  each discrete segment[22].

ground water, unconfined.  Water in an
  aquifer that has a water table.
  Synonymous with phreatic ground
  water[22].

grout. A fluid mixture of cement and water
  (neat cement) of a consistency that can be
  forced through a pipe and placed where
  required. Various additives, such as sand,
  bentonite, and hydrated lime may be
  included in the mixture to meet certain
  requirements. Bentonite and water are
  sometimes used for grout[6].

grout curtain. The filling of void spaces in
  rocks  to prevent the flow of water into
  and through the rock; most commonly
  associated with dams.

grouting.  The operation by which grout is
  placed between the casing and the sides of
   a well bore  to a predetermined height
   above the bottom of the well. This
   secures the  casing in place and excludes
   water and other fluids from the well
   bore[6].

 grunkarst. See subsoil karst.

 gryke.  Seegrike.
                                             87

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guano. An accumulated deposit of animal
  excrement. In caves it is most commonly
  associated with bat colonies, but cave
  dwelling birds such as swifts may also
  contribute. Guano is only abundant in
  tropical regions and may be dry and
  powdery, or a foul, wet, sludge — as in
  the Niah Caves of Sarawak. It is a vital
  food source for many troglobites.
  Consisting mainly of phosphates and
  nitrate it is valued as a fertilizer or an
  ingredient of explosives and has
  commonly been mined. Over 100,000
  tons of bat guano have been extracted
  from Carlsbad Caverns, USA[9]. See also
  cave guano.

guano cave. A cave containing large
  amounts of guano[I3].  See also cave
  guano.

guanobia.  An animal association feeding
  on guano. Not considered true
  cavernicoles as guano is not confined to
  caves.

gulf. Steep-walled closed depression having
  a flat alluviated bottom; in some gulfs a
  stream flows across the bottom[10J.

gull. A widened fissure formed by land
  slipping along valley sides, generally
  where massive beds such as limestone
  overlie weaker rocksCT. See also tectonic
  cave; windypit.

gully. A deep erosional channel[16].

gushing spring. See spring, vauclusian.

gypsum. 1. White or colorless mineral or
  rock composed of the hydrated calcium
  sulfate, CaSO4.2H2O. Gypsum rock is  an
  evaporite precipitated from sea water and
  is therefore soluble in water and may
  contain dissolutional caves.  Mineral
  gypsum is formed in some caves by
  reactions between the host limestone and
  sulfates (including sulphuric acid) derived
  from oxidized sulfide minerals (see
  pyrite). Gypsum, also referred to as
  selenite, commonly occurs as [transparent
  crystals, blades, needles or fibres in cave
  clay deposits. A more spectacular  form is
  as fibrous or curved crystals that may
  develop into cave flowers on cave walls
  and ceilings, as for example in parts of
  the Flint Mammoth Cave System, USA,
  or grow into large, hanging chandeliers,
  as in Lechuguilla Cave, New Mexico[9]. 2.
  A mineral composed of hydrous calcium
  sulfate[10], CaSCy2H20.      !

gypsum cave.  Both vadose and jphreatic
  caves can form in gypsum, which is very
  soluble in water, but they are uncommon
  because gypsum rock rarely survives total
  dissolution in the near-surface
  environments associated with explorable
  caves. Gypsum caves certainly exist at
  depth within buried evaporate; sequences.
  In areas of wet climate gypsuih caves are
  generally seen only if encountered  by
  man-made excavations,  hi contrast,
  gypsum caves are more common and
  more extensive in areas that have
  experienced a long period of dominantly
  arid  climate.  The most spectacular
  gypsum caves are in the Podoh'e region of
  the Ukraine, where joint  guided maze-
  cave systems are very extensive —
  Optimisticeskaja has around 180km of
  passsage[9).                 !
                             i
gypsum flower.  See cave flowejr.
                                            88

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gypsum karst.  A karst landscape developed
  on, or perhaps above, gypsum or similar
  evaporite rock sequences.  Dissolution of
  gypsum by ground water in buried,
  interstratal, situations is common and the
  effects of such dissolution maybe
  expressed at the land surface in the form
  of subsidence depressions.  There are
  extensive areas of gypsum karst in North
  America and the Ukraine but British
  examples are limited to rare caves,
  exposed by quarrying, and subsidence
  depressions above dissolved gypsum
  beds, such as those around Ripon,
  Yorkshire191.
                                            89

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                    H
   a tube remaining in the roof or wall of a
   cave[IO]. See also tube.       :
habitat. The immediate surroundings
   (living place) of a plant or animal;
   everything necessary to life in a particular
   location except the organism itself1231.

hade.  The angle of inclination of a fault (or
   joint) plane measured relative to the
   vertical191. See also dip.

Halbhohle. (German.) See rock shelter.

Halbkugelkarst. (German.) Tropical karst
   topography containing dome-shaped
   residual hills surrounding depressions, a
   kind of Kegelkarst. Also called
half-exposed karren. These are patches of
   soil on otherwise bare limestone that
   attack the rock by means of biogenic
half-blind valley.  Blind valley in which the
   stream overflows in floodtime when the
   swallow hole can not accept all the
   watertl0].

half tube; half-tube.  1. An inverted
   channel with semi-circular cross .section
   seen in cave-passage ceilings, most
   clearly where the ceiling is an uneroded
   bedding surface.  The half tube originates
   as part of a phreatic tube guided by the
   bedding plane, and the lower half is
   subsequently removed by vadose
   enlargement. The presence of half tubes
   provides important evidence of early
   phreatic-cave development^1. 2. Trace of
Hagen-Poiseuille equation. The equation
   used to define the laminar flow of water
   in either fractures or tubes and is given as

                     \v3bydh
            Q =  -
                          dL
   for laminar flow in fractures  '•

   and

             Q _  _  nr4ydh  i
                      8|J.  dL

   for laminar flow in tubes     '••

   which states that the average volumetric
   discharge of flow through either type of
   opening is directly proportional to the
   type, shape, and dimensions of a
   particular pore and the hydraulic
   gradient151. Note: g=discharge, w=width
   of the fissure, 6=open portion ;of the long
   dimension of the fissure, r=radius of the
   tube, y and ju are the specific weight and
   dynamic viscosity of water respectively,
   dMf.L=gradient, and a minus sign is
   attached to the equations to indicate that
   flow occurs in the direction of deceasing
   hydraulic head.

halite. The mineral form of sodium chloride
   (NaCl), or rock salt. Halite occurs,
   sometimes to considerable thicknesses, in
   many buried-rock successions, from
   which it has been extracted both by
   mining and by redissolving it in water
   pumped from and back to the surface.
   The existence of brine springs [indicates
   that natural water movement occurs
                                            90

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  through buried halite sequences,
  presumably through voids that could be
  thought of as caves. Although distinctive
  halite (or salt) karst features are known in
  some arid areas, a range of features
  analogous to those found on karstic rocks
  such as limestone are unlikely to form,
  and less likely to be preserved, due to
  halite's relative weakness and very high
  solubility.  In Britain expressions of salt
  karstification are limited to relatively
  subdued surface features. The "flashes"
  of the Cheshire area, are hollows,
  sometimes transformed into water-filled
  meres, formed by subsidence of overlying
  rocks and superficial deposits where salt
  has been dissolved from buried halite
  beds of Triassic age191.

hall.  In a cave, a lofty chamber which is
  much longer than it is wide[10]. See also
  gallery.

halocliiie. A locally steep salinity gradient
  along the interface between fresh ground-
  water and saline ground-water, such as is
  found at the base of the freshwater lens
  common beneath many limestone islands
  in the tropics. Water mixing and
  microbial activity are important
  influences on dissolution along the
  halocline, as shown for instance in blue
  holes[9].

halomoirphic soil. Saline and alkali soils.

hanging blade. A blade projecting down
   from the ceiling[10]. See also blade.

hannaytte.  A cave mineral —
   (NH4)2Mg3H4(P04)4-8H2Otn].

hardening. The process of induration[16].
hardness.  1. Property of water that prevents
  lathering because of the presence of
  cations, mainly calcium and. magnesium,
  which form insoluble soaps[10]. 2. The
  sum of calcium and magnesium ions
  expressed as the equivalent amount of
  calcium carbonate (CaCO3)[16]. 3. The
  property to form insoluble salts of fatty
  acid (soap)[16].

hardpan.  This develops when there are
  secondary calcium carbonate
  cementations hi the lower part of the soil
  profile[16].  Synonym: mortar bed. See
  also caliche; havara; nari.

harness. An arrangement of tape for
  attaching the lower body (seat harness) or
  the upper (chest harness) to ascenders or
  descenders[25].

havara. Name given in Cyprus to a soft
  porous carbonate formation, up to several
  meters thick, found capping many
   formations and containing fragments and
  minerals derived from older rocks; it is
  probably a type of hardpan or caliche[20].
   See also caliche; kafkalla.

haystack hill. (Puerto Rican.) In the
   tropics, rounded conical hill of limestone
   developed as a result of solution. Term
   replaced by mogote[101.  Synonyms:
   (French.) mogote; (German.) Mogote;
   (Italian.) mogote, rilievo carsico residua;
   (Spanish.) mogote; (Turkish.) konik
   kiregta^i tepesi; (Yugoslavian.) hum. See
   also mogote.

head. The energy contained in a water
   mass, produced by elevation, pressure, or
   velocity163.
                                             91

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head loss.  That part of head energy which is
   lost because of friction as water flows[6].

head, static. The height above a standard
   datum of the surface of a column of water
   (or other liquid) that can be supported by
   the static pressure at a given point.  The
   static head is the sum of the elevation
   head and the pressure head1221.

head, total. The total head of a liquid at a
   given point is the sum of three
   components: (a) the elevation head,
   which is equal to the elevation of the
   point above a datum, (b) the pressure
   head, which is the height of a column of
   static water that can be supported by the
   static pressure at the point, and (c) the
   velocity head, which is the height to
   which the kinetic energy of the liquid is
   capable  of lifting the liquid[22].

head water. The upper reach of a stream[161.

heat of condensation. The heat released in
   transforming a substance from its vapor
   to its liquid state[16].

heat of vaporization.  The heat necessary to
   change water from the liquid to  the
   gaseous state[16].

heel-print karren. See Trittkarren.

helictite.  1. Generally small variety of
   stalactitic calcite growth that is twisted
   and contorted with no apparent regard for
   gravity.  Helictites form on cave walls,
   ceilings, and on stalactites.  The growth
   develops as seepage water loses carbon
   dioxide  from near its tip, having been
   supplied to that point by capillary action
   through  a fine central canal. The helictite
  shape is created by crystal lattice
  distortion and crystal form changes within
  the calcite, but what causes these is
  uncertain.  Impurities may plan a role, and
  rare groups of parallel growing helictites
  maybe wind-guided[9].  2. Irregular, twig-
  like, crystalline growths with varying
  orientations but often in crystal
  continuity, formed in caves by
  precipitation from bicarbonate
  solutions[20].  3. A curved or angular
  twiglike lateral projection of calcium
  carbonate having a tiny central canal,
  found in caves[10]. Also known as
  eccentric anemolite[20]; eccentric
  stalactite. Synonyms: (French.)
  excentrique; (German.) exzentrisch
  gekrummter, Tropfstein, Excentriques;
  (Greek.) stalaktits akanonistos; (Italian.)
  stalattiti anomale, eccentiche; (Spanish.)
  estalactita excentrica; (Turkish.)
  duzensiz sarkit; (Yugoslavian.) helifait.
  Related to curtain, dripstone, speleothem.

heligmite. An eccentric growing upward
  from a cave floor or from a shelf in a
  cave. A curved or angular thin stalag-
  mite™.

helmet. A miner's,  climber's or other kind
  of non-metallic, protective helmet used in
  caving.

hematite. A cave mineral — Fe2O3[11].
                              i
hemimorphite.  A cave mineral;—
  Zn4Si2O7(OH)2-H2O[11].

herbivore. An animal that eats plants, thus
  making the energy stored in plants
  available to carnivores[23]. See also
  carnivore; insectivore; omnivore.
                                             92

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heterogeneity.  A characteristic of a
  medium in which material properties v|ry
  from point to point[22].

heterogeneous. The unequal spacial
  distribution of aquifer properties1161.

hexahydrite. A cave mineral—:
  MgSO4-6H2O[111.

hibbenite. A cave mineral —
  Zn7(PQ4)4(OH)2-7H2Olni.

hibernation. A prolonged dormancy or
   sleeplike state in which animal body
  processes such as heartbeat and breathing
   slow down drastically and the animal
  neither eats nor drinks.  Nearly all
   cold-blooded animals and a few
   warm-blooded animals hibernate during
   the winter in cold climates. Extremely
   large aggregations of bats, crickets, and
   spiders hibernate in some caves1231.

histo, histoplasmosis. The disease caused
   by the fungus Histoplasma capsulatum,
   found in bird and bat guano, especially in
   the southern USA and the tropics. An
   occupational disease of cavers, aviary and
   poultry workers, guano miners, and
   maintenance workers. Infection is usually
   caused by breathing the microscopic
   spores, which infect the lungs, or
   sometimes the eye.  Flu-like symptoms
   accompanied by low-grade fever,
   breathing difficulties and pain, and
   miasma may start about 14 days after
   exposure and continue for weeks, months,
   or rarely until death, usually from
   complications. Treatable with various
   anti-fungals, such as itroconazole. Often
   misdiagnosed, as the standard tests may
   give a false negative1231.
hod. See aisle.

holokarst. 1. Karst area with little or no
   surface runoff or streams; it is underlain
   by thick carbonate rocks and is
   characterized by well developed karst
   surface topography from karren to poljes,
   extensive subsurface karst features like
   caves, caverns, galleries, chimneys, etc[20].
   2. Cvijic's term for a karst area like that
   of the Dinaric Karst of Slovenia. Such
   areas have bare surfaces on thick deposits
   of limestone that extend below sea level,
   well developed karren, dolines, uvalas,
   poljes, deep ponors, and extensive cave
   systems; they have little or no surface
   drainage1101. Synonyms: (French.)
   holokarst; (German.) Holokarst; (Greek.)
   holokarst; (Italian.) olocarsismo,
   carsismo, maturo; (Spanish.) holokarst;
   (Turkish.) tarn karst; (Yugoslavian.)
   potpuni kfs(kras), holokarst. Contrast
   causse, merokarst.

 homogeneity. A characteristic of a medium
   in which material properties are identical
   everywhere1221.

 homogeneous. The even spacial
   distribution of aquifer properties1161.

 homogeneous fluid. A fluid that occurs in a
   single phase[16].

 hook gage. A gage for the precise position
   measurement of liquid levels1161.

 hopeite. A cave mineral —
   Zn3(P04)2-4H20[111.

 horizontal angle. The difference in
   direction of two survey lines measured
   clockwise  in a horizontal plane[25].
                                              93

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horst.  A block having been uplifted along
   its boundary faults[16].

Horton number. Expresses the relative
   intensity of erosion process in a drainage
   basin1161.

hot-seat rappel. A method of rappelling in
   a cave with the rope running under one
   leg, up across the opposite shoulder and
   controlled with a hand.  The friction of
   the rope on the body creates a lot of heat,
   hence its name[13].

hoya, hoyo. (Spanish.) A very large closed
   depression. Used in Puerto Rico for
   doline, in Cuba for poljecl01.

hum.  1. Karst inselberg. Residual hill of
   limestone on a fairly level floor, such as
   the isolated hills of limestone in poljes.
   In some tropical areas, used loosely as
   synonym for mogote[10].  2. Yugoslavian
   term for an isolated residual hill on the
   bottom of a polje[20]. Synonyms:
   (French.) butte temoin; (German.)
   (Karstinselberg), Hum; (Greek.) karstiki
   martyree lophi; (Italian.) testimoni
   carsici; (Russian.) karstovij ostanec;
   (Spanish.) hum; (Turkish.) karst
   adatepesi; (Yugoslavian.) hum. See also
   karst inselberg; mogote.

humidity, absolute. The moisture content
   by weight per unit volume of air[16].

humidity, relative. The ratio, expressed as
   a percentage, of the amount of water
   vapor actually present in air of a given
   temperature, as compared with the
   greatest possible amount of water vapor
   that could be present in air at that
   temperature. Calculation of relative
  humidity can be done from tables, special
  slide rules or calculators, graphs, or
  complex equations1231. See also
  hygrometer; psychrometer.  >

humus-water grooves. This is a special
  type of meandering karren or wall karren
  in which the water originated in humus
  covering.  Water originating from a
  humus cover has an excess of CO2 and is
                             i    '•
  therefore, very aggressive and can
  dissolve large amounts of limestone.
  Thus humus-water grooves can be very
  deep but after approximately 2-3 meters,
  the grooves flatten out and continue as
  normal meanders or wall karren[3]. See
  also meander karren; wall karren.

huntite.  A cave mineral —
  CaMg3(C03)4[11].

hydration. The act by which a substance
  takes up water by absorption and/or
  adsorption161.

hydraulic barrier. A general term referring.
  to modifications of a ground-water flow
  system to restrict or impede movement of
  contaminants1221.

hydraulic conductivity. 1. A
  proportionality constant relating hydraulic
  gradient to specific discharge Which for
  an isotropic medium and homogeneous
  fluid, equals the volume of water at the
  existing kinematic viscosity that will
  move in unit time under a  unit hydraulic
  gradient through a unit area measured at
  right angles to the direction of flow'221. 2.
  The volume of water that will move
  through a medium in a unit of time 'under
  a unit hydraulic gradient through a unit
  area measured perpendicular to the
                                            94

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  direction of fiow[22].  3. The ability of a
  rock unit to conduct water under specified
  conditions1101.  It is typically expressed as
  gpd/ft2, ft/day, or m/day.

hydraulic conductivity, effective. The rate
  of flow of water through a porous
  medium that contains more than one
  fluid, such as water and air in the
  unsaturated zone, and which should be
  specified in terms of both the fluid type
  and content and the existing pressure.

hydraulic diffusivity.  See diffusivity,
   hydraulic.

hydraulic discharge.  The discharge of
   ground water through springs or wells[16].

hydraulic fracturing. The formation of
   artificial fractures in rock systems around
   a well by high pressure fluid injections1161.

 hydraulic gradient.  1. The change in static
   head per unit of distance in a given
   direction. If not specified, the direction
   generally is understood to be that of the
   maximum rate of decrease in head[22!. 2.
   Slope of the water table or potentiometric
   surface1221. 3. A chance in the static
   pressure of ground water expressed in
   terms of the height  of water above a
   datum, per unit of distance in a given
    direction1221.

 hydraulic head. The height above a datum
    plane (such as sea level) of the column of
    water that can be supported by the
    hydraulic pressure at a given-point in a
    ground-water system.  For a well, the
    hydraulic head is equal,  to the distance
    between the water level in the well and
    the datum plane1221.
hydraulic jump.  1. A standing surge of
  water passing from below critical depth in
  open channel flow1161; often occurs in
  caves. 2. An abrupt depth variation in
  rapidly varying channel flow[16].

hydraulic profile. A vertical section of the
  potentiometric surface1161.

hydraulic radius. The ratio of the filled
   cross-sectional area to wetted
   perimeter1161.

hydrochemical facies.  Distinct zones that
   have cation and anion concentrations of
   diagnostic chemical character of water
   solutions in hydrologic systems which is
   describable within defined composition
   categories1221.

 hydrocompaction.  The process of volume
   decrease and density increase that occurs
   when moisture-deficient deposits compact
   as they are wetted for the first time since
   burial1211. Synonym: shallow subsidence.

 hydrogeologic. Those factors that deal with
    subsurface waters and related geologic
    aspects of surface waters.

 hydrograph,  characteristic. A hydrograph
    based on the unit step process.

 hydrodynamic dispersion. l.The
    spreading (at the macroscopic level) of
    the solute front during transport resulting
    from both mechanical dispersion and
    molecular diffusion[22]. 2. The dynamic
    dispersion  of fluid particles in'fiow
    through a porous medium due to velocity
    changes in the pore channels1161.
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hydrodynamic dispersion, coefficient of.
   See dispersion coefficient.

hydrogeochemistry. The geochemistry of
   water as related to the occurrence of
   subsurface water[16].

hydrogeologic. Those factors that deal with
   subsurface waters and related geologic
   aspects of surface waters[6].

hydrogeologic unit. 1. Any soil or rock
   unit or zone which by virtue of its
   hydraulic properties has a distinct
   influence on the storage or movement of
   ground water122'.  2. Means a soil or rock
   unit or zone which by virtue of its
   porosity or permeability, or lack thereof,
   has a distinct influence on the storage or
   movement of ground water122'.

hydrogeology. The study of subsurface
   waters in their geological context[16].

hydrograph.  1. A graph relating stage,
   flow, velocity, or other characteristics of
   water with respect to time[22'. 2. A time
   record of stream discharge at a given
   cross section of the stream or of the
   stream surface elevation at a given
   point[I6'.

hydrograph separation. The separation of
   a hydrograph into its different
   components to analyze flow
   contributions116'.

hydrography. The geographical description
   of water bodies on the earth's surface116'.

hydrologic barrier. See barrier,
   hydrologic.
hydrologic budget. The quantitative
  accounting of all water volumes and their
  changes over time for a given basin or
  province1'61.

hydrologic properties. Those properties of
  a rock that govern the entrance of water
  and the capacity to hold transmit, and
  deliver water, such as porosity, effective
  porosity, specific retention, permeability,
  and the directions of maximum and
  minimum permeabilities[22].   '
                              i
hydrology. The study of atmospheric,
  surface, and subsurface waters and their
  connection with the water cycle[16].

hydromagnesite.  A cave mineral —
  Mg5(C03)4(OH)2-4H20["].    !

hydrometeorology. Meteorology dealing
  with water in the atmosphere1161.
                              [
                              i
hydrometric station.  A station |at which
  there usually are a number of hydrometric
  measurements being performed[16l

hydrometry. The science of water
  measurements^6',            j
                              t
hydrophilic.  Having a great affinity for
  water*16'.                    !

hydrophobic. The repelling of water[16].

hydrophyte.  A plant requiring large
  amounts of moisture for growth[16].
                              i

hydrosphere. That part of the e^rth that
  contains liquid  or solid water[!6].

hydrostatic pressure. The pressure due to a
  column of water[25].          ;
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hydrostratigraphic unit. See
  hydrogeologic unit.

hydroxylapatite. A cave mineral —
  Ca5(P04)3(OH)tni.

hydrozincite. A cave mineral —
hypogean. Pertaining to, or living in,
  regions deeper than the endogean zone.
  See' also epigean.
hyetograph. A graph of rainfall intensity
   against time[16].

hygrometer. 1. An instrument that reads
   the humidity in the air directly; some are:
   based on a hair's ability to shrink or
   expand with humidity, or on certain
   electronic chips. Generally, a
   psychrometer is more accurate at higher •
   humidities (above 95%)[23]. 2. Apparatus
   for the direct measurement of the relative
   humidity in the  atmosphere[16].  See also
   psychrometer.

hygroscopic nucleus.  Small solid particles
   around which water condensates (cloud
   formation)1161.

hydroscopic water. Condensed water at a
   solid surface[16l

hypogeum. The subterranean
   environment[23].

 hypolimnion.  A deep layer in stratified
   water[16].

 hydroscopic coefficient.  The amount of
   absorbed water on the surface of soil
   particles in an atmosphere of 50% relative
   humidity at 25°C[16].                  ;
                                             97

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ice. Crystallized water formed below the
   freezing point (H2O)[16].

ice cave. 1. Any cave in rock that is partly
   filled with ice.  The term should not be
   applied to glacier caves.  The ice may
   form in massive icicles and flows, when
   percolation water from unfrozen rock
   seeps into a cave containing freezing air
   drawn in from outside. This is a seasonal
   situation in many alpine caves, and if
   winter freezing exceeds summer melting
   the ice may become permanent, as in
   Austria's Dachstein and Eisriesenwelt
   caves. Alternately water vapor may
   crystallize out as hoar frost, commonly
   forming large hexagonal ice crystals that
   line the walls of a freezing cave, as in
   Grotte Valerie, northern Canada[9]. 2. A
   cave, generally in lava or limestone, in
   which the average temperature is below
   0°C., and which ordinarily contains
   perennial ice. Ice may have the form of
   stalactites, stalagmites, or flowstone[10].
   (French.) glaciere; (German.) 'Eishohle';
   (Greek.) paghomenon spileon; (Italian.)
   ghiacciata naturale, grotta ghiacciata;
   (Russian.)  ledjanaja pescera; (Spanish.)
   cueva helada, cueva de hielo\ (Turkish.)
   buz magarasi; (Yugoslavian.) ledena
   pedna, ledenjdcd, ledena jama. See
   glacier cave.

Hlite. A clay mineral.

imbibition.  1. The absorption of a fluid,
   usually water, by a granular rock or other
   porous material, under the force of
   capillary attraction, and in the presence of
   pressure.  2. Fluid displacement in porous
   media as a result of capillary forces
  only1161. 3. Absorption of water by plants.
  Synonym: capillary percolation.

immiscible. 1. Two or more liquids that are
  not readily soluble[22]. 2. The chemical
  property of two or more phases that, at
  mutual equilibrium, cannot dissolve
  completely in one another, e.g., oil and
  water[22]. 3. The quality of liquids
  exhibiting a clear interface where they are
  in contact; not miscible[I61.
                              i
impermeable. A characteristic of some
  geologic material that limits their ability
  to transmit significant quantities  of water
  under the pressure differences ordinarily
  found in the subsurface[22].    !

impervious.  Not permitting the;fiow of
  water[16].                    \

impervious lens.  An impermeable, lens-
  shaped body of sediment in an otherwise
  permeable aquifer[I6].         !

imported water.  Water coming from
  outside the ground-water basin under
  consideration1161.             !

impound. The collecting of water by
  damming[I6].                 i

inception.  The earliest stage of i
  speleogenesis. The start of the inception
  phase marks the transition from 'rock
  with no caves' (in the widest sense) to
  'rock with caves', and extends through
  whatever time interval is required for
  gravitational laminar flow conditions to
  be established in a given situation (see
  gestation and initiation)'91.    \
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inception horizon. A part of a rock
   succession that is particularly susceptible
   to the effects of the earliest cave forming
   processes and hence is critical to the
   origin of most non-tectonic caves. By
   virtue of physical, lithological or
   chemical deviation from the predominant
   carbonate facies within the sequence, it
   passively or actively favors the localized
   inception of dissolutional activity191.  See
   also inception.

incision.  See entrenchment.

initiation. The early parts of speleogenesis,
   generally up to the point of breakthrough
   from laminar to turbulent flow, at an
   average conduit diameter of 10mm.
   Initiation includes, but is not the same as,
   inception191.

inclinometer. An instrument to measure the
   inclination of surfaces1161.

incoherent material. Unconsolidated
   material163.

 incrustation. 1. Deposition of a crust (of
   calcite, etc.) upon an object by
   precipitation from water oversaturated
   with salts (calcium bicarbonate, etc.)[201.
   2. The deposition of mineral matter by
   water[16].  Synonyms: (French.)
   incrustation; (German.) Krustenbildung;
   (Greek.) epiphlioma; (Italian.)
   incrostazione; (Russian.) obrazovanie
   natecnih kor; (Spanish.) incrustcion;
   (Turkish.) kabuk baglama, kabukla§ma;
   (Yugoslavian.) inkrustacija.

 induced activity.  The activity or response
    of a system that has been subjected to an
    artificial excitation1161.
induced infiltration. An increase in
  infiltration from a surface water body by
  the lowering of the original water table[16].

induced recharge.  A method of
  withdrawing ground water at strategic
  points to induce natural recharge[16].

indurated rock.  A rock that has been
  hardened and solidified by diagenetic
  processes1161.

infiltrability. The ease of infiltration1161.

infiltration. The downward entry of water
   into the soil or rock[22].

infiltration basin.  A basin in which water
   is spread for recharge.

infiltration capacity. The maximum rate at
   which a soil or rock is capable of
   absorbing water or limiting infiltration1221.

infiltration gallery. A horizontal conduit
   for the purpose of intercepting ground
   water[16].

 infiltration index.  The average rate of
   infiltration throughout a given rain
   storm[16].

 infiltration rate. 1. The rate at which a soil
   or rock under specified conditions
   absorbs falling rain, melting snow, or
   surface water expressed in depth of water
   per unit time1221.  2. A characteristic
   describing the maximum rate at which
   water can enter the soil or rock, under
   specified conditions, including the
   presence of an excess of water. It has the
   dimensions of velocity^21.
                                              99

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infiltrometer. Apparatus for measuring the
   amount of infiltration[16].

inflow cave, influent cave. Cave into
   which a stream flows or formerly
   entered[10].

influent stream.  See losing stream.

infrared light. Light not visible to the
   human eye, with wavelengths longer than
   those of visible red light and shorter than
   those of radio waves[23].

initial abstraction. The maximum amount
   of rainfall absorbed without producing
   runoff1161.

inject, to. 1. The introduction of
   pressurized fluids into a porous
   subsurface formation1161.  2. The
   introduction of tracer materials (e.g.
   fluorescent dyes) into the subsurface.

injection head. A swivel head connector
   through which drilling fluid is injected
   into the drill pipe[16].

injection well. Well used for emplacing
   fluids into the subsurface[22].

injection zone. A geological 'formation,'
   group of formations, or part of a
   formation receiving fluids through a well.

injectivity. The capacity of a well or
   formation to accommodate pumped in
   liquid1161.

inlet cave. A cave developed beneath a
   swallow hole where a surface watercourse
   first passes underground in karst
   limestone[19].
input point. Points where water enters an
  underground drainage route or aquifer.
  An obvious type of input point is a
  surface sink or swallow hole, where
  allogenic drainage has direct access to a
  conduit system within a carbohate
  aquifer.  Less obvious are points where
  drainage enters a potential carbonate
  conduit-system from adjacent non-
  carbonate strata (such as a porous
  sandstone aquifer) or where water utilizes
  a fracture system to pass through
  otherwise relatively impermeable beds
  and into the carbonate aquifer?91.
                              i
insectivore. An animal that feeds on
  insects.  Almost all species ofNorth
  American bats are insectivores[23].  See
  also carnivore; herbivore; oirinivore.

in-situ density.  The density of \jvater
  measured at its actual depth[22l.  See also
  potential density.            '•
                              I
insulated stream.  A stream neither
  receiving nor abstracting wate)r from a
  ground-water body because of an
  impermeable bed[16].          ;

insurgence. A term proposed to' describe a
  point of inflow for surface water into
  subsurface conduits.  It has not gained
  wide usage and is not recommended for
  use. Diffuse insurgence may be used to
  describe the slow percolation of water
  through overburden and tight pores in the
  rock. Confluent insurgence may be
  applied to water entering the rpck via
  identifiable streams sinking into the
  subsurface while a confluent insurgence
  complex would apply to a  cluster of
  insurgences. Abandoned insurgences is
  the term applied to inflow points no
                                            100

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  longer used by infiltrating water. An
  overflow insurgence is the term used to
  describe insurgences utilized only during
  periods of high flow[123.

intake area, recharge area. The surface
  area in which water is absorbed into an
  aquifer eventually to reach the zone of
  saturation[10].

interaqidfer flow. The flow that occurs
  between aquifers through fracture
  openings or through the wellbore[16].

interbedded. Pertaining to beds or
  sedimentary material intercalated in a
  parallel fashion into a main stratum[16].

interbedding. A bed between layers of
  different material[I6].

interception.  The abstraction of direct
  rainfall on vegetation cover[16].

interception loss. That part of rainfall
  retained by the aerial portion of
  vegetative cover[16].

interdigitation. The lateral interlocking of
   sedimentary series[16].

interface. 1. The contact zone between two
   materials of different chemical or
   physical composition[22].  2. The contact
   plane of two immiscible liquids[16].

interference. The condition occurring when
   the area of influence of a water well
   comes into contact with or overlaps that
   of a neighboring well, as  when two wells
   are pumping from the same aquifer or are
   located near each other[6].
interflow.  Subsurface runoff161.

intergranular stress. The stress between
   grains in a solid matrix[16].

intergranular voids. Generally primary or
   secondarily enhanced voids within rocks,
   with average dimensions of 0.001 to
   O.lmm.  Such voids, or pores, may
   provide  interconnected porosity in many
   karst rocks and allow early water
   movement under laminar flow
   conditions[9].

intermittent spring.  See spring,
   intermittent.

intermittent stream, intermittent river.  1.
   A stream or river which flows only in
   direct response to precipitation or to
   intermittent discharge of a spring; not
   confined to karst areas, but not
   uncommon in them[20]. 2. A  stream or
   river that flows at irregular intervals[16].
   Synonyms: (French.) cours d'eau
   intermittent; (German.) intermittierender
   Flu/3,  episodischer periodischer FluJ3;
   (Greek.) dialipon potamos; (Italian.)
   torrente intennittente; (Spanish.)
   corriente intermitente; (Turkish.) kesintili
   akarsu; (Yugoslavian.) suslca,  suvaja.
   Contrast with interrupted river.

intermontane basin. A basin lying between
   two mountain ranges[16].

internal drainage. Drainage in a closed
   basin and not reaching the sea[16].  It is
   common in maturely karsted terranes
   where surface water bodies are relatively
   nonexistent.
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interstice. 1. An opening in a rock or soil
   that is not occupied by solid matter[22]. 2.
   An opening or space which may be
   occupied by air, water, or other gaseous
   or liquid material1221.  Synonymous with
   void, pore.  See also pore; pore space;
   porosity; porosity, effective; porosity,
   primary; porosity, secondary.

interstitial ice. Ice occurring below the  '
   surface in soil pores[16].

interstitial medium. Spaces between grains
   of sand or fine gravel filled with water
   which contains phreatobia[25].

interstitial water. Water held in small
   wedge like interstices at grain contact[16].
interstratal karst; interstratal
   karstification. 1. Features formed by the
   dissolutional removal of all or part of a
   buried rock unit.  Interstratal-karst
   features are common within 'highly
   soluble evaporite rocks such as gypsum
   and halite, and may be equally common,
   but less readily recognized, within the
   preserved remnants of carbonate
   successions. Interstratal karst should not
   be confused with buried karst.  The finest
   interstratal karst in Britain is the
   extensive cave development in the
   limestones beneath the Namurian
   Millstone Grit plateaux of South Wales,
   where the large collapse dolines in the
   Millstone Grit are interstratal-karst
   landforms[9]. 2. The process of
   karstification of highly soluble rocks
   (e.g., gypsum, anhydrate, and salt) that
   are overlain by less soluble rocks (e.g.,
   shales), but are still selectively dissolved
   by circulating ground water[10].
interstratal karst. Karst topography that is
  covered by and developed beikeath pre-
  karst rock or sediment and may or may
  not be part of the contemporary
  landscape. It is younger than its cover
  and is formed by the solution of soluble
  rock in the subsurface, most commonly
  beneath relatively insoluble rock such as
  sandstone or chert.  The term refers to
  areal solution rather than to cave
  development but is also applicable to
  rejuvenated mantled karst and rejuvenated
  buried karst. Subsoil karst is transitional
  to interstratal karst[17]. Synonyms:
  (French.) karst sous-jacent; (German.)
  unterirdisches Karstphanomdn; (Greek.)
  kalymenon karst; (Italian.) carso coperto;
  (Spanish.) karst interstradal; (Turkish.)
  tabakalar arasi karst. See also buried
  karst;  denuded karst;  covered'karst.

inter-permafrost karst. See permafrost
  karst;  sub-permafrost karst.

interrupted river, interrupted Stream.  1.
  A river which flows for part of its course
  on the surface, and part underground in
  caves[20].  2. A stream interrupted over
  space[16].  3. A discontinuous stream[16].
  Synonyms: (French.) riviere interrompue;
  (German.) periodischer Flufl ?, Karstflufi,
  versickernder FluJ3; (Greek.) :
  thiakekomenos potamos; (Russian.)
  peresihauchaj reka, syhaja reka;
  (Spanish.) rio sumente; (Turkish.) yeryer
  akan nehir; (Yugoslavian.) susica,
  suvaja, periodicka rijeka (reka). See
  also lost river; intermittent stream.

intrinsic permeability. See pernaeability,
  intrinsic.
                                             102

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inundation. The covering of an area by
   flood waters1161.

invaded zone.  In geophysical well logging,
   the zone in which an appreciable amount
   of mud filtrate has penetrated1161.

invasion.  In geophysical well logging, the
   penetration of a fluid into the porous
   medium1161.

invasion depth. The depth to which drilling
   mud filtrate penetrates into a
   formation[16].  '

invertebrate.  An animal, such as a
   planarian, snail, or crayfish, without a
   backbone1231. See also vertebrate.

inverted siphon. See water trap.

ion. An element or compound that has
   gained or lost an electron so that it is no
   longer neutral electrically and now carries
   a charge161.

ion mobility.  The ease with which ions
   move in an electrolytical solution[I6].

irreducible saturation. The lowest water
   saturation obtainable by mechanical
   reduction methods1161.

irrigation. The artificial watering of fields
   for crop production1161.

irrigation requirement. The water needed
   for crop production exclusive of
   precipitation1161.

irrigation return flow. The part of
   artificially applied water that is not
   consumed by evapotranspiration and that
  migrates to an aquifer or surface water
  bodyf.

irrotation flow. Potential flow or flow with
  no rotational component'161.

isobath. A line of equal depth1161.

isochrone. A line connecting water levels
  in observation wells for a given instant in
  time'161.

isohyet. A line of equal rainfall'161.

isopiestic line.  A contour on a piezometric
  surface connecting points of equal static
  level'161.

isopleth.  A line of equal distance from the
  point of outflow of abasin[16].

isopotal line. A line of equal infiltration
  capacity1161.

isotherm. A line of equal temperatures[161.

isotope tracer. Tracer which is an isotope
  of an element present in the water; it may
  be artificial (added to water) or natural
  (present in the water)[20].  Synonyms:
  (French.)  traceur isotopique', (German.)
  Markierung durch radioaktive Isotopen;
  (Greek.) isotopicos ichnithetis; (Italian.)
  tracciante isotopico; (Russian.) izotopnij
  indikator; (Spanish.) trazador isotopico;
  (Turkish.) izotop izleyicisi;
  (Yugoslavian.) izotopni traser.

isotropic. Equal properties in all directions.

isotropic mass. A mass having the same
  property or properties in all directions'221.
                                             103

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isotropy.  The condition in which the
  property or properties of interest are the
  same in all directions[22].

izdan. A general Yugoslavian term for a
  ground-water reservoir from which
  ground water may readily be extracted; it
  is not specifically a karst term[201.
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jama.  1. (Slavic.) Vertical or steeply in-
   clined shaft in limestone, known as abime
   or aven in France and as pothole in
   England. 2. Any cave[10].  Synonyms:
   (French.) jama; (German.) Abgrund,
   Schacht, Schlund; (Greek.) karstikon
   phrear; (Italian.) abisso, foiba, pozzo,
   voragine; (Russian.) karstovij kolodec,
   karstovaja sahta; (Spanish.) sima, pozo,
   avenc; (Turkish.) obruk; (Yugoslavian.)
   bezdan, japaga, zvekara, pekel, brezno,
   prepad, propast. Related to cenote,
   doline, obruk, pit, shaft, shake hole.

jarosite. A cave mineral —
   KFe3(S04)2(OH)/11].

joint.  1. A break of geological origin in the
   continuity of a body of rock occurring
   either singly, or more frequently in a set
   or system, but not attended by a visible
   movement parallel to the surface of the
   discontinuity. 2. A junction or
   connection of mechanical elements such
   as drill pipe[16]. See also fracture.

joint diagram. A diagram constructed by
   accurately plotting the strike and dip of
   joints to illustrate the geometrical
   relationship of the joints within a
   specified area of geologic investigation.

 joint or fault set. A group of more or less
   parallel joints or faults.

 joint or fault system. A system consisting
   of two or more joint or fault sets or any
   group of joints or faults with a
   characteristic pattern (e.g., radiating,
   concentric, etc.).
joint pattern. A group of joints which form
   a characteristic geometrical relationship,
   and which can vary considerably from
   one location to another within the same
   geologic formation.

joint-plane cave.  A cavity high in relation
   to width developed along steeply dipping
   joint planes[10].

jumar. An ascender with a simple
   finger-operated safety catch, a handle and
   several attachment points[25].

juvenile water. Water that has not been
   part of the hydrosphere before and is
   derived from the earth's interior[16].
                                             105

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                    K
kafkalla. A tenn used in Cyprus for the
   hardened upper portion of crust of
   havara[20]. See also caliche; havara.

kame. A stratified glacial sand and gravel
   deposit forming a small, conical hill[16].

Kamenica, Kamenitza. (German, possibly
   of Slavic origin; plural, Kamenice.) A
   small depression (a few meters in
   diameter and several centimeters deep) in
   a level calcareous surface, enlarged by the
   solution effect of water collecting
   between slight undulations.  It is
   developed vertically at first by stagnant
   water; the steep sides thus evolved then
   induce the flow of water which flutes the
   slope and so eventually widens the basin.
   Sediments and low orders of plant life
   frequently collect on the even floor, the
   latter aiding further solution by
   reactivating the^H of the water[19].
   Synonyms:  (French.) kamenice;
   (German.) Opferkefiel; (Greek.) lakouva,
   ythrolakkos; (Russian.) bljudoe;
   (Spanish.) cuenco, tinajita; (Turkish.)
   erime tavasi; (Yugoslavian.) kamenica,
   skalne kotlice, scalba, skalnica.  See also
   solution pan; water pot.

kankar; kunkar. (Australian.) See caliche.

Kannelierungen. (German.) See
   Rillenkarren.

kaolin.  A common clay mineral[I6].

karabiner. See carabiner.

Karren.  (German.) Channels or furrows,
   caused by solution on massive bare
   limestone surfaces; they vary iin depth
   from a few millimeters to more than a
   meter and are separated by ridges. In
   modern usage, the terms  are general,
   describing the total complex of superficial
   solution forms found on compact pure
   limestone. Classified into several kinds,
   the  most common of which are:
   Rillenkarren — shallow channels  sepa-
   rated by sharp ridges 2-3  centimeters
   apart; Rinnenkarren — flat-bottomed
   grooves several centimeters apart;
   Kluftkarren —joints enlarged by solu-
   tion; Spitzkarren — large deep grooves
   extending down from steep spires  or
   pinnacles; meandering karren|
   (Mdanderkarren) — small winding or
   meandering channels; round karren
   (Rundkarreri) — karren having rounded
   channels and intervening rounded  ridges,
   probably reexhumed after formation
   under soil or peat; Flachkarren — equiv-
   alent to the English dint; Boaenkarren —
   karren formed beneath the soil[10].
   Synonyms: (French.) lapies; (German.)
   Karren, Schratten; (Greek.) j
   thaktyloglyphae, amaxotrochiae; (Italian.)
   campo solcato; (Russian.) karji;
   (Spanish.) lapiaz; (Turkish.) erime olugu;
   (Yugoslavian.) skrape, skripovi, grizine,
   zlebici, skraplje.            >

Karren, free.  (German.) Bare kjarst; water
   flows unhindered over the limestone
   surface[3].                  ;

Karrenfeld; Karren field.  (German.) An
   area of limestone dominated by karren[10].
   These appear as bare karst and consist of
   the sum of exposed and half-exposed
   karren, occasionally also of covered
   karren which have become exposed.
   They range in size from a few, hectares to
                                           106

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  a few hundred square kilometers131.
  Synonym: (Turkish.) erime olugu
  See also clint; grike.
karst.  (Internationally used term, originally
   the German form of the Slavic word kras
   or krs, meaning a bleak waterless place; it
   is the German name for a district east of
   Trieste having such terrane.) A terrane,
   generally underlain by limestone or
   dolomite, in which the topography is
   chiefly formed by the dissolving of rock,
   and which may be characterized by
   sinkholes, sinking streams, closed depres-
   sions, subterranean drainage, and
   caves[10]. The term karst unites specific
   morphological and hydrological features
   in soluble (mostly carbonate) rocks.
   Morphological features include karren,
   do Unas (sinkholes), jamas, ponors,
   uvalas, poljes, caves, caverns, etc.
   Hydrological features include basins of
   closed drainage, lost rivers, estavelles,
   vauclusian springs, submarine springs,
   more or less individualized underground
   streams and incongruity of surface and
   underground divides.  Karst is understood
   to be the result of natural processes in and
   on the earth's crust cause by solution and
   leaching of limestones, dolomites,
   gypsum, halite, and other soluble rocks[20].
   Synonyms: (French.) karst; (German.)
   Karst ; (Greek.) karst; (Italian.) carso,
   carsismo; (Russian.) karst; (Spanish.)
   karst; (Turkish.) karst; (Yugoslavian.)
   krs, kras. See also buried karst; cone
   karst; covered karst; exhumed karst;
   Halbkugelkarst; Holokarst; Kegelkarst;
   Merokarst; microkarst; naked karst;
   paleokarst; pseudokarst; relict karst;
   Spitzkegelkarst; subjacent karst;
   syngenetic karst; thermokarst; tower
   karst.
karst aquifer.  See aquifer, karst.

karst barre. (French.)  1. A karst terrane of
   limited area completely surrounded by
   rocks of low permeability1101. 2. Term for
   karst areas whose lower part is enclosed
   and bordered by more or less impervious
   rocks which impedes ground-water flow
   out of the karst area.  Synonyms:
   (French.) karst barre; (German.)
   Riegelkarst; (Greek.) phragmenon karst;
   (Spanish.) karst cerrado; (Turkish.) setli
   karst; (Yugoslavian.) zagaceni kfs(kras),
   zajezeni kras.

karst base level. Level below which
   karstification does not or has not taken
   place[I01.  Synonyms: base level of
   karstification1201; (French.) niveau de base
   karstique; (German.) Korrosionsniveau;
   (Greek.) basis apokarstoseos, or better
   'patoma apokarstoseos'; (Italian.) livello
   di base della attivitd Corsica; (Spanish.)
   nivel de base kdrstico; (Turkish.)
   karstla^ma tabani; (Russian.) bazis karsta;
   (Yugoslavian.) baza krskog procesa, baza
   karstifikacije, baza zakrasevanja.

 karst breccia.  See collapse breccia;
   solution breccia.

 karst bridge.  A natural bridge or arch in
   limestone[10].

 karst couvert. (French.) See covered karst.

 karst fens.  1. Marshes developed in
   sinkhole terrain; swampy solution fens[10].
   2. Marsh or swamp formed by plants
   overgrowing a karst lake or seepage.
   Synonyms: (French.) marais karstique;
   (German.) Karstsumpfl; (Greek.)
   karstikon elos; (Italian.) palude o
                                             107

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   acquitrinio carsico; (Russian.) karstovoje
   boloto; (Spanish.) laguna karstica;
   (Turkish.) karst batakligi; (Yugoslavian.)
   lokva, kal.

karst fenster.  See karst window.

karst fossile.  (French.) See buried karst.

karst hydrology.  1. The branch of
   hydrology dealing with hydrological
   phenomena on and in regions and areas
   composed totally or in part of rocks
   which are soluble in water, such as
   limestones, dolomites, gypsum, and
   halite1201. 2. The drainage phenomena of
   karstified limestones, dolomites, and
   other slowly soluble rocks[10]. Synonyms:
   (French.) hydrologie karstique;
   (German.) Hydrologie des Karsts;
   (Greek.) karstike hydrologia; (Italian.)
   idrologia carsica; (Russian.) gidrologija
   karsta; (Spanish.) hidrologia karstica;
   (Turkish.) karst hidrolojisi;
   (Yugoslavian.).

karst inselberg. A residual hill of soluble
   rock in a porje[20].  Synonyms: (French.)
   inselberg karstique; (German.)
   Karstinselberg (Hum, Mogote); (Greek.)
   karstiki martyres lophi; (Italian.) rilievo
   carsico residua; (Russian.) karstovij
   ostanec; (Spanish.) relieve kdstico
   residual; (Turkish.)  karst tepesi;
   (Yugoslavian.) hum.

karst lake.  1. Lakes on karst surface,
   frequently connected with ground water;
   lakes in subterranean hollows (caves and
   caverns)[20]. 2. A large area of standing
   water in extensive closed depression in
   limestone1101. Synonyms: (French.) lac de
   karst; (German.) Karstsee; (Greek.)
   karstiki limni; (Italian.) lago carsico;
   (Russian.) karstovoe ozero; (Spanish.)
   lago kdrstico; (Turkish.) karstikgolu;
   (Yugoslavian.) krsko (krasko)Jezero.
                              i
karst margin plain. A plain generally on
   limestone between higher country of
   limestone on one side and of less pervious
   rocks on the other, but having a cover of
   impervious detritus, which allows surface
   drainage1'01.

karst noye. (French.) See drowned karst.

karst nu. (French.) See exposed karst.

karst plain.  1. Large flat surface in karst
   formed by erosion and corrosion[20]. 2. A
   plain on which closed depressions,
   subterranean drainage, and other karst
   features may be developed.  Also called
   karst plateau[IO]. Synonyms: (French.)
  plateau karstique; (German.) Karstebene,
   Karstrandebene, Korrosionsfldche;
   (Greek.) karstikon pedhion; (Italian.)
  piano carsico; (Russian.) karstovaja
   ravnina; (Spanish.) llanura karstica;
   (Turkish.) karst ovasi;   (Yugoslavian.)
   krska zaravan, povrs, kraski ravnik. See
   also marginal polje.          j

karst polje. See polje.         '•
                              \
karst pond. Closed depression in a karst
   area containing standing watef[10].

karst river. 1. A river (or stream) flowing
   in a karstic area, either on the surface of
   the ground or through an underground
   cave system[20].  2. A river that originates
   from a karst spring1101.  Synonyms:
   (French.) riviere karstique; (German.)
  Karstflu/3; (Greek.) karstikos potamos;
                                            108

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   (Italian.) corso d'acqua carsico;
   (Russian.) karstovaja reka; (Spanis!^) rio
   kdrstico; (Turkish.) karst nehiri;
   (Yugoslavian.) krka rijeka, kraska reka.

karst seep. Place where karst ground water
   oozes out at the surface of the ground;
   sometimes overgrown and then forming a
   karst fen[20].  Synonyms: (French.)
   suitement karstique; (German.)
   Karstgrundw after-Austritt; (Greek.)
   karstiki thiaroi; (Russian.) visacivanie
   karstovih vod; (Spanish.) zona de
   absorcion; (Turkish.) karst smntisr,
   (Yugoslavian.) mocilo.

karst shaft. A vertical or steeply-sided
   natural opening a few tens to a few
   hundred meters deep, formed by solution
   or erosion of vertical or sub-vertical
   fractures or fissures by down flowing
   surface water.  Such a pit, formed from
   above, may connect with a chimney
   formed from below.  Synonyms: (French.)
   karst shaft; (German.) Schacht, Schaft;
   (Greek.) karstikos lakkos; (Italian.)
   voragine, inghiottitoio; (Russian.)
   karstovaja sahta; (Spanish.) sima;
   (Turkish.) karst bacasi; (Yugoslavian.)
  jama. Related to dolina, jama, obruk, pit.

karst sous-jacent. (French.) See interstratal
   karst.

karst spring. See spring, karst.

karst topography.  Topography dominated
   by features of solutional origin[10].
   Geomorphically, the dominant features
   usually but not always obviously present,
   are sinkholes and caves.  In tropical
   regions, karst towers (e.g. mogotes) may
   also dominate the landscape.
karst valley. 1. Valleys in karst are
   normally distinctive due to the lack of
   integrated surface drainage. Most are
   either blind (due to being closed where
   the drainage sinks underground), headless
   or pocket (where a river emerges from a
   spring) or dry  (where surface flow has
   been lost due to underground capture).
   The exception is the allogenic valley,
   where a river completely traverses a karst,
   normally because underground conduits
   at or below valley floor level are
   immature. Fine examples of allogenic
   karst valleys are Dove Dale in the Peak
   District and France's Tarn Gorge[91. 2.
   Elongated solution valley in limestone[20].
   3. Valley produced by collapse of a
   cavern roof1101.  Synonyms: (French.)
   vallee karstique; (German.) Karsttal,
   Karstgafie; (Greek.) Karstiki Mas;
   (Italian.) valle Corsica; (Russian.)
   karstovaja dolina; (Spanish.) valle
   kdrstico; (Turkish.) karst vadisi;
   (Yugoslavian.) krska (kraska) dolina.

karst vert. See subsoil karst.

karst water. Water discharged from karst
   springs which posses characteristics,
   primarily that of calcium content,
   indicating solution during the passage of
   that water across and through karst
   limestone. That part of karst spring water
   which is derived from watercourses
   sinking into the rock (and therefore
   originates mainly on impermeable rock) is
   said to be allogenic; that which derives
   from precipitation over the karst area
   alone is said to be autochthonous - the
   distinction between resurgence and
   exsurgence waters[19].
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karst well. Terra applied to features that
  result from the solution enlargement and
  rounding of joints (grikes) to produce
  cylindrical pits[8]. See also grike; joint.

karst window.  1. Depression revealing a
  part of a subterranean river flowing across
  its floor, or an unroofed part of a cave. 2.
  A small natural bridge or arch which can
  be seen through[10]. 3. A through opening
  in natural limestone walls, formed by the
  joining of karst grottos as a result of
  dissolution processes[20]. Synonyms:
  (French.) fenetre karstique; (German.)
  Karstfenster; (Greek.) karstikon
  parathyron; (Italian.) finestra carsica;
  (Russian.) karstovoe okno; (Spanish.)
  dolinaen ventana; (Turkish.) karst
  penceresi; (Yugoslavian.) krsko  (krasko)
  okno.

karstic. Occasionally used as the adjective
  form of karst[10) and pertaining to karst
  landforms or processes[19].

karstification.  1. The processes of solution
  and infiltration by water, mainly chemical
  but also mechanical, whereby the surface
  features and subterranean drainage
  network of a karstland are developed to
  form a karst topography, including such
  surface features as dolines,'karren, arid
  mogotes and such subsurface features as
  caves and shafts. An area currently or
  formerly undergoing karstification,  and
  thus characterized by karst landforms, is
  said to be karstified1191. 2. The process by
  which karst is formed. The term has been
  given a wide range of meaning, from
  almost a synonym or corrosion of soluble
  rocks by water to a term comprising all
  processes responsible for the
  development of karst features including,
  besides corrosion, such phenomena as
  mechanical erosion, jointing, and
  faulting1201. Synonyms: (French.)
  karstification; (German.) Verkarstung;
  (Greek.) apokarstosis; (Italian.)
  carsificazione; (Russian.)    ;
  karstoobrazovanie; (Spanish.)
  karstificacion; (Turkish.) karstla§ma;
  (Yugoslavian.) okrsavanje, zakrasevanje,
  karstijikacija.               \

karstland. A region characterized by karst
  topography[10].              :

Karstrandebene.  (German.) See karst
  margin plain.                \

katavothron. (Greek.) A closed depression
  or swallow hole[10].          i
                              i
Kegelkarst.  (German.) A general term used
  to describe several types of tropical
  humid karst characterized by numerous,
  closely spaced cone-, hemispherical-, or
  tower-shaped hills having intervening
  closed depressions and narrow
  steep-walled karst valleys or |
  passageways[10]. See also cockpit karst;
  cone karst; Halbkugelkarst; tower karst.

keld. See rising.
                              !

kernmantel rope. A rope with a plaited
  sheath around a core of parallpl or twisted
  strands[25].                  \

krab.  See carabiner.

keyhole passage; keyhole.  1. This very
  descriptive name derives from the cross-
  sectional shape of a cave passage that
  consists of a phreatic tube with a vadose
  canyon cut in its floor. It is the classic
                                            110

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  example of a two-phase cave passage that
  originated and began its development in
  the phreas and was then modified by
  vadose entrenchment. As this sequence is
  the result of water table lowering by
  normal surface erosion, keyholes are
  common. Some keyholes are so small
  that the lower slot is impassable and the
  caver has to squeeze along the upper tube;
  others are very large.  Spectacularly long
  is the 5km of keyhole forming the
  Fissures in Castleguard Cave, Canada.  A
  tube 6m in diameter tops an irregular
  tapering canyon 15m deep that must be
  traversed on sloping ledges at mid-level[9].
  2. A small passage or opening in a cave;
  in cross section, rounded at the top,
  constricted in the middle, and rectangular
  or flared out below[10]. They appear as
  keyholes when viewed in cross section.
  They are formed when underground
  streams flowing in a tubular passage
  begin downcutting to form a canyon
  passage^151. See also canyon passage;
  passage; tubular passage; vertical shaft.

klinkenberg effect. The slip of gas
  molecules at the pore wall giving
  apparently higher permeability than
  would be obtained by liquid
  measurements^61.

Kluft. See aisle.

Kluftkarren.  (German.) See grike.

knobstone.  Speleothem, larger, more
  pronounced, and more widely separated
  than cave coral[10].

knots. Various methods of securing or tying
  ropes or webbing material together by
  cavers[13]. See also prusik knot; prusiking.

kras; krs. A Slavic word meaning bleak,
  waterless place, from which the term
  karst is derived[10]. See also karst.

Kugelkarst.  See Halbkugelkarst.

kunker.  See caliche.
                                            Ill

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laboratory coefficient of permeability,
   standard coefficient of permeability.
   Permeability defined for controlled
   temperature conditions (60°F) as gallons
   per day per square foot (gpd/ft2) under a
   unit gradient1161. See also Meinzer unit.

labyrinth. See network;  maze cave.

lacustrine formation.  A sedimentary
   formation of lacustrine origin.

ladder. In caving, a flexible, lightweight
   ladder of galvanized or stainless steel
   wires and aluminium alloy rungs[25].

lag time.  A time lapse between the onset of
   a given event and the produced results[I6].

lagoon. A body of relatively shallow water
   near a sea shore, with or without a direct
   connection to the sea[16].

lake. 1. As used in speleology, a body of
   standing water too deep to walk acrosstl0].
   2. In caving, a body of standing water in a
   cave, but used for what would be called a
   pond or pool on the surface[25].  3. A body
   of fresh inland water[16].

laminar flow. Flow in which the head loss
   is proportional to the first power of the
   velocity1223. Water flowing in a laminar
   manner will have streamlines that remain
   distinct and the flow direction at every
   point remains unchanged with time.
   Synonymous with streamline flow,
   viscous flow.

lamination.  The layering or very thin
   bedding of sedimentary rocks[16].
landfill.  A general term indicating a
  disposal site for refuse, dirt from
  excavations, junk[6], and hazardous
  wastes.                     ;

land-form. A topographic feature of the
  earth's surface[16].            |

land pan. An evaporation pan used to
  measure evaporation from a land surface;
  pan is usually mounted at the land
  surface[16].                   !

land subsidence. The subsidence of a
  surface due to a loss of support[I6].  Often
  occurs as a result of over pumping
  underlying aquifers or as a result of
  mining activities.  In karst terranes,
  subsidence can occur as a result of man-
  made changes to the natural hydrologic
  system (ground-water withdrawals or
  storm-water injection) or as a [
  consequence of the natural dissolution
  process. Subsidences may be sudden or
  progress slowly over time.    i

land surface. That part of the lithosphere
  usually not covered by water[1f].

land-use. A  particular utilization of a land
  surface especially with respect to its
  influence on the hydrologic cycle[161.

landslide. The sliding down of earth and
  rock on a slope[16].           ;

lapies. (French; sometimes spelled lapies or
  lapiaz.) Term for a region with outcrops
  of small regular pillars, cones, or blocks
  of carbonate rock[20].  Synonyms:
  (French.) lapies; (German.) Karren;
  (Greek.) lapiaz, lenar; (Italian.) lapia,
  solcato, carregiato; (Russian.) karri;
                                            112

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  (Spanish.) lenar; (Turkish.) crime olugu,
  lapya; (Yugoslavian.) skrapa, grizine,  '
  bridine, zlebici. See karren, rock-rill.*
  grikes.

larva (plural larvae). An active immature
  stage in an animal's life history when its
  form usually differs from the adult form,
  such as the grub stage in the development
  of a beetle or the tadpole stage in the life
  history of a frog[23]. See also
  metamorphosis; pupa.

lateral line system.  A series of sensory
  organs, usually appearing in a line or
  series of lines on the sides and heads of
  fishes and larval amphibians. The system
  enables the animal to sense vibrations in
  the water[23]. See also cupula; neuromast.

lateral moraine. A glacial deposit at the
   flank of a glacier, often constituted by
   debris from valley walls[16].

laterite. A tropical ferruginous clay soil[16].

lateritic soil.  A red colored soil with high
   iron oxide content1161.

lava bed.  A lava flow of considerable areal
   extent and relatively small thickness1161.

 lava cave, lava tube.  1. A cave that formed
   in a partly cooled, broadly basaltic or
   phonolitic lava, not by erosion but by
   molten material flowing away.  In most
   cases, an initial active lava conduit is
   formed when  a flowing surface lava
   stream has a roof grow over it by
   accretion of chilled solidified material.
   Insulated inside its conduit the lava can
   continue to flow and develop an airspace
   above it, which is preserved as an
  explorable cave when completely cooled.
  Most lava caves are just very long tubes,
  though branching and multiple levels may
  occur as dictated by flow patterns and re-
  invasions of older tubes. On Kilauea
  Volcano, Hawaii, the Kazumura Cave is
  47km long and descends 888m, but its
  tubes, mostly 5m in diameter, lie less than
  20m beneath the sloping surface of the
  lava[9]. 2. A cave in a lava flow, generally
  formed by gas blistering the surface or by
  lava flowing out from beneath a solidified
  crust, forming a tube or tunnel[10]. 3. An
  empty tubular supply channel from which
  liquid lava has drained[16]. See also lava
  karst; pseudokarst.

lavakarst. A non-karst term.  Subsurface
  openings formed in lava flows due to
  outflow of liquid lava from beneath a
  solidified crust or due to gas blisters.
  Tubes or tunnels are formed with such
  pseudokarst features as lava stalactites
  and also collapse structures and basins of
  closed drainage.  Lava karst does not arise
  through solution of the rock by circulating
  water .and thus is not a true karst[201.
  Synonyms:  (French.)pseudo-karst;
  (German.) (Vulkanischer Karst), Lava-
  Karst, Pseudokarst; (Greek.)
  pseudokarst; (Italian.) pseudocarsismo
  vulcanico; (Spanish.) volcanokarst
   (general), tubo volcanico (tube, tunnel),
  jameo (collapse structure), malpais
   (topographic feature similar to lapies);
   (Turkish.) lav karsti, a Idatici karst. See
   also lava cave; pseudokarst.

 lay. The way in which strands of a rope or
   cable are twisted[25].

 layer. A sheetlike deposit of sedimenttl6].
   Bed or stratum of rock[16].
                                              113

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leachate.  1. Materials removed by the
  process of leaching[22]. 2. A liquid that
  has percolated through soil rock or waste
  and has extracted dissolved or suspended
  materials1221.

leaching. 1. The removal of materials in
  solution from soil, rock, or waste[22]. 2.
  Separation or dissolving out of soluble
  constituents from a porous medium by
  percolation of water[22].

lead. A passage noticed but as yet
  unexplored1251.

lead-acid cell. A rechargeable acid battery
  for use with an electric cap lamp[25].

leader. In caving, the person directing the
   activities of a caving party, especially
  with regard to safety1251.

leak. An opening in an aquiclude that
   permits penetration of water from other
   formations into the main aquifer[I6].

leakage.  1. The flow of water from one
   hydrogeologic unit to another. The
   leakage may be natural, as through
   semi-impervious confining layer, or man-
   made, as through an uncased well[221. 2.
   The natural loss of water from artificial
   structures as a result of hydrostatic
   pressure1221.

leakage factor. The factor describing
   leakage flow into or out of a leaky
   aquifer1161.

leakance.  1. The ratio K'/b', in which K'
   and b' are the vertical hydraulic con-
   ductivity and the thickness, respectively,
   of the confining beds[22]. 2. The rate of
  flow across a unit (horizontal); area of a
  semipervious layer into (or out of) an
  aquifer under one unit of head difference
  across this layer. Synonymous with
  coefficient of leakage1221.     |
                              I
leaky aquifer. Aquifers, whether artesian
  or water-table, that lose or gain water
  through adjacent less permeable layers[22].

lecontite. A cave mineral—   ;
  (NH4,K)Na(S04)-2H20[11].   j
                              I
leg. A part of a survey traverse Between two
  successive stations1251.       •,

leucophor.  One of a family of optical
  brightening agents that have b'een used
  with some degree of success in water-
  tracing experiments.  It has no color, but
  is readily detected by its distinctive
  fluorescence under ultra-violent light[9].

levee. An artificial bank to prevent
  overbank flow of a rivertl6].  j
                              t
level.  1. Within a cave, a group 'of passages
  developed in the same horizontal plane[10].
  2. The altitudinal relation of a cave floor
  to an outside surface[10]. 3. The surface of
  water in a well or standing reservoir[16].

lift. The vertical pumping distance between
  the water level in a well to the land
   surface[I6].
                              i
light hole. (Jamaican.) 1. A hole in the roof
   of a cave through which light j enters;
   sometimes a nonfunctioning swallow
   hole[20].  2. Fossil or abandoned swallow
                                             114

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lime.  Calcium oxide, CaO; used loosely and
  incorrectly in referring to limestone[10].:

lime sink.  See  sinkhole.

limestone. Sedimentary rock containing at
  least 50% calcium carbonate by weight.
  The purer limestones consist almost
  entirely of calcite; less pure rocks maybe
  referred to as, for example, muddy
  limestone. Some limestones are porous
  with diffuse permeability; these rarely
  become truly cavernous, though some
  fissure flow may occur. Where ground-
  water flow in less porous rocks is
  restricted to bedding related fissures and
  secondary fractures it can, even when
  moving very slowly, corrode the almost
  entirely soluble rock and lead to true cave
  development191.

limestone pavement.  1. A level, or gently
   inclined, bare limestone surface scored
   and fretted by karren.  The stripping of
   soil or cover rocks to expose the bare
   rock pavement is a glacial process, and
   the development of the karren — both the
   dissolutional enlargement of the joints
   and also the dissolutional carving of
   runnels — is largely post-glacial.
   Limestone pavements are characteristic
   features of glaciokarst and occur
   extensively in the north of England, in the
   Burren of County Clare in Ireland and on
   many high alpine limestones[9]. 2. A bare
  • plane surface of limestone, parallel to the
   bedding, commonly divided into blocks
   (clints, Flachkarren) by solutionally
   widened joints (grikes, Kluftkarren), and
   pitted by solution pans[1°!. 3. A
   glaciokarstic landform, produced on a
   glacially planed limestone surface which
   has subsequently become dissected into
  blocks (clints or dalles) by solution-
  enlargement of vertical joints[19].  3.
  Horizontal or sloping platforms of bare
  limestone whose surface usually
  coincides with bedding-plane partings of
  the rock; often eroded into clint and
  grikes rock forms[20]. Synonyms:
  (French.) plateforme calcaire; (German.)
  Kalk Plattform, Limestone Pavement;
  (Greek.) karstikon lifhostroton;
  (Spanish.) lapiaz entrecruzado; (Turkish.)
  kiregta^i do^emesi.  See also clints;
  grikes; Karrenfeld.

limestone sink, see sinkhole.

limnology. The study of lakes[I6].

line of seepage.  See seepage line.

lineation. The parallel orientation of
  structural features that are lines rather
  than planes.  Some examples are parallel
  orientation of the long dimensions of
  minerals, long axes of pebbles, striae on
  slickensides, and cleavage-bedding plane
  intersections.

lintel line. A line on the ground at a cave
  entrance perpendicularly beneath the
  outer edge of the rock above; may or may
  not coincide with the dripline[25]. See also
  driplme.

liquid. An incompressible or nearly
  incompressible fluid.

liquid medium.  Contains the aquatic
   cavernicoles[25].

lithologic factor.  The factor influencing
   composition, texture, and sequence of
   rock types[I6].
                                             115

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lithology. 1. The physical characteristic of a
  rock, including composition, grain size,
  texture, degree of cementation (or
  lithification) and structure, that determine
  the rock type191. 2. The physical
  properties and aspect of a rock[16].

lithosol. A rocky soil[16].

lithosphere. That part of the earth's crust
  containing solid rocks[16].

lithostratigraphy. A formal naming system
  that allows the description of rock
  successions in terms of recognizable
  defined units on a local scale. The units,
  which comprise supergroups, groups,
  formations, members and beds in
  decreasing order of size, are described on
  the basis of observable characteristics193.

littoral zone. The coastal strip where rocks
  that are above sea-level are in contact
  with rocks that are generally below sea-
  level. Where suitable aquifer conditions
  occur across the littoral zone, notably
  around relatively young carbonate islands,
  fresh ground-water interfaces with saline
  ground-water atthe halocline and
  dissblutional processes are enhanced by
  mixing water and, possibly, by microbial
  effects191.

live cave. Cave in which there is river
  action or active deposition of
  speleothems. Compare active cave[10].

LNAPL. Abbreviation for light nonaqueous
  phase liquid. Liquids falling into this
  category have specific gravities that are
  less than water (the specific gravity for
  water is usually taken to be one), are
  relatively immiscible with water, and tend
  to migrate downwards througlj the vadose
  and to float on top of the water table. See
  also LNAPL; immiscible; NAPL.
                              i
loam.  Calcareous clay[16].       >
                              E
localized circulation. Circulation in karst
  aquifers in which the water moves in
  certain preferred zones and does not
  occupy all or most of the openings below
  this level[IO].  Synonyms: (French.)
  circulation preferentielle; (German.)
  Ortlich begrenzte Karstwafier-
  Zirkulation; (Italian.) circolazione
  Corsica parziale; (Spanish.) circulation
  localizada; (Turkish.) yersel dola§im;
  (Yugoslavian.) lokalizirana (Ipkalna)
  cirkulacija. Compare diffuse [circulation.
                              I
lodgement till. Glacial till deposited from
  slowly melting ice at the base of a
  glacier[I6].

loess. Fine-grained and poorly consolidated
  windblown sediment, mainly of silt.
  Great thicknesses of loess are found in
  areas marginal to hot and cold deserts,
  where the prevailing wind deposits fine
  dust particles blown from the desert
  basins or out of glaciofluvial sediments.
  Loess is a common allogenic component
  of soils on limestones. Large numbers of
  artificial caves have been excavated in the
  hillsides of soft loess in central China191.

longitudinal fault.  A fault having the same
  direction of strike as the surrounding
  strata[16].                    ;

longitudinal section; long section. A
  section along the length of a cave passage
  or chamber or combination of these, or
  along a survey traverse in a cave[251.
                                             116

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loosest packing. The three-dimensional
   arrangement of particles with the highest
   possible void volume per unit cell[16].

losing stream. A stream or reach of a
   stream in which water flows from the
   stream bed into the ground[22].  hi karst
   terranes, losing streams may slowly sink
   into fractures or completely disappear
   down a ponor.  Synonym: influent stream.
   See also ponor;  stream sink.

lost circulation. The result of drilling fluid
   escaping from a borehole into the
   formation by way of crevices within the
   formation161. It is a common occurrence
   in most karst aquifers due to the existence
   of large subsurface voids that  are
   sometimes intersected during  a drilling
   program.

 lost river. 1 •. A surface river or stream
   flowing onto or over karst that then
   disappears completely underground
   through a swallow hole (ponor) and
   which may or may not rise again and flow
   as a resurgent surface river or stream1201.
   2. hi a karst region,  a surface  stream that
   enters an underground course1101.
   Synonyms: (French.) perte de riviere;
   (German.) Flufiversickerung,
   Flufichwinde; (Greek.) chanomenos
   potamos; (Russian.) iscezajuscaja reka;
    (Spanish.) rio sumente; (Turkish.) kayip
    nehir; (Yugoslavian.) ponornica,
   ponikalnica. See also ponornica; sinking
    stream. Compare intermittent river.

  lower confining bed. An impermeable bed
    underlying an aquifer1161.

  lower course. The part of a water course
    near a discharge point[16].
low flow. The lowest sustaining flow during
  base runoff conditions of a river[16].

Lycopodium spores. 1. The spores of a club
  moss, with individual structures about
  0.03mm in diameter. Easily transported
  by and almost indestructible in cave
  water, the spores can be dyed a variety of
  colors, and offer a valuable water-tracing
  technique. Preparation and collection of
  the spores is very tedious, and the method
   lacks the convenience of using simple
   dyes[91. 2. Spores of Lycopodium
   clavatum, which can be used in natural or
   dyed color as a label in studying
   ground-water movement in karst areas1101.

 lysimeter.  A device for measuring
   percolation and leaching losses from a
   column of soil under controlled
   conditions[22].
                                             117

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                   M

Ma. Internationally accepted abbreviation
   for million years, commonly applied to
   measurements of geological time. This
   abbreviation is currently used in
   preference to My[9].

macrokarst. Karst area with large
   morphological features. The term is not
   easily defined because it lacks limits[20].
   Synonym; (Italian.) merocarsismo.
   Compare microkarst.

macropore. A pore with dimensions such
   that capillary forces become less
   important during flow[I6].

magnesian limestone. Common but loose
   synonym for dolomitic limestone or
   dolomite rock. The magnesian limestone
   of northern England is a rock sequence of
   Permian age that includes a locally
   variable number of beds of dolomitic
   limestone191.

magnesite.  A cave mineral — MgCO3[11].

magnetic north. The direction to the north
   magnetic pole at a given place and time.
   This differs from the direction towards
   which the north end of a compass points
   by a small individual compass error and
   by the effect of any local magnetic
   attraction1251.

malachite. A cave mineral —
   Cu2(C03)(OH)2tnl

mammals. The class of animals that
   includes bats, mice, man, and many
   others.  They typically have a body
   covering of hair and give birth to living
   young, which are nursed on milk from the
   mother's breast[23].

manatial. (Spanish.) Spring.  See also
   spring.

Manning equation. An equation used to
   compute the velocity of uniform flow in
   open channel: V=1.486/n R2/3 S1/2, where
   V is the mean velocity of flow (in cfs
   units), R is the hydraulic radius in feet, S
   is the slope of the channel or sine of the
   slope angle, and n is the Manning
   roughness coefficient111.  See also Chezy
   equation; Froude number; Reynolds
   number.                    .

manometer. A pressure measuring device
   for determining the hydraulic head
   developed by a flowing fiuid[I^.
                             f
mantled karst. Karst topography that is
   wholly or partly covered by a relatively
   thin veneer of post-karst rock pr sediment
   and is part of the contemporary
   landscape[17). See also buried karst;
   covered karst.

marble. 1. Metamorphosed and;
   recrystallized carbonate rock tjiat is
   generally capable of supporting cave
   development. For example much of the
   Antro del Corchia in Italy and many caves
   in the South Nordland area of Norway
   have formed in marble[9].  2. Limestone
   recrystallized and hardened by heat  and
   pressure. 3. Commercially, any limestone
   that will take a high polish[IO].
                             i
marine  relict.  An animal whose presently
   extinct ancestors lived in salt water but
   became adapted to life in fresh water
                                           118

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  when an area formerly covered by the sea
  became dry land[23].

marine water.  Ocean water having invaded
  coastal aquifers[16].

marginal polje. 1. Flat plain surrounded by
  higher limestone country on all except
  one side which consists of impermeable
  ridges or hills.  Such a feature is normally
  found on the edge of a karst area or
  region1201. 2. Flat limestone plain which is
  surrounded by higher country but is
  bordered on one side by impervious
  rock[!01.  Synonyms: (French.) polje
  marginal; (German.) Randpolje,
  Semipolje; (Greek.) perithoriakon 'polje';
  (Italian.) polje marginale; (Spanish.)
  polje marginal; (Turkish.) kenar golova;
  (Yugoslavian.) rubno polje, robno polje.
  See Randpolje. Compare blind valley.

marker bed. A bed with characteristic
  features that can be followed over large
  areas for identification purposes[16].

marl. Unconsolidated sedimentary rock
  consisting largely of calcium carbonate
  and clay; usage varies from calcareous
  clay to earthy limestone, and in some
  parts of the United States, the term has
  been used for any unconsolidated
  sedimentary rock containing fossil
  shells™.

mass curve.  A graph of cumulative values
  of a hydrological quantity against time1151.

mass density. Mass per unit volume of a
   substance[16].

mass flowmeter. A measuring device for
  mass flow rates[16].
massive structure.  A homogenous
  structure without any oriented features1'61.

master cave. Best defined as a low level
  trunk streamway cave with many
  tributaries. The old concept of the master
  cave being formed at the water table
  should be disregarded. The Leek Fell
  Master Cave, in the Yorkshire Dales, is
  2km long, partly a vadose canyon, partly a
  drained phreatic tube and partly a
  submerged tube.  Part of it therefore lies
  below the water table while elsewhere its
  presence controls the water table.  The
  French equivalent, 'collecteur', is more
  descriptive of the master cave's true role.
  The depth to a currently active master
  cave is dictated by interactions between
  local topography, stratigraphical factors
  and geological structure.  In the low hill
  karst of England and Kentucky, active
  master caves lie at depths of around
  100m, but in Monte Canin, Italy, and the
  Hautla Plateau, Mexico, they lie at depths
  of 1000m. The collecteur of the Gouffre
  Berger, France, is met just 250m down
  but can be followed to a depth of over
  1000m, down the dipping limestone beds,
  thus emphasizing the local dominance of
  stratigraphical over topographical
  factors191.
match point.  A common point in the
   superposition of a type curve over
   measured data in aquifer test analyses.

matric potential.  The energy required to
   extract water from a porous medium to
   overcome the capillary and adsorptive
   forces1221.
                                            119

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matrix. The solid framework of a porous
  system1221.

maximum basin relief. The elevation
  difference between basin mouth and
  highest point within a basin perimeter[I6].

maze cave. A cave with an essentially
  horizontal network of interconnecting and
  mainly contemporaneous passage loops.
  Three broad types of maze cave have
  been described — anastomotic, network
  and spongework — and these may be
  subdivided on the basis of how they
  developed by slow-moving water,
  restricted to a confined, artesian aquifer,
  or by water that is ponded due to
  backflooding.  A mechanism of
  potentially great importance, particularly
  in the context of the inception of network
  maze caves, is multiple, diffuse input
  from adjacent, permeable but non-
  cavernous rocks. Spectacular joint-
  guided maze caves such as Knock Fell
  Caverns and the Devis Hole Mine
  Caverns occur in the thin Yoredale
  limestones of the northern Pennines, but
  the most extensive mazes are in the Black
  Hills of Dakota,*USA (including Jewel
  Cave) and in the Ukrainian gypsum karst
  (including Optimisticeskaja)[9]. See also
  maze cave pattern.

maze cave pattern. A cave system which
  consists of a labyrinth of intersecting
  passages of rather uniform character that
  form closed loops. See also anastomotic
  cave pattern; maze cave; network cave
  pattern; spongework cave pattern.

mean deviation. A linear mean of absolute
  deviations116^.
mean value. The statistical average or
  measure of central tendency[16l
                             i
                             [
meander. 1. Overdeveloped and self-
  exaggerated bend is a stream course either
  on the surface or underground;, caused by
  more erosion on the outside than on the
  inside of a bend due to natural wash of
  the flow. Undergound meanders
  commonly originate within bedding plane
  guided elements of the phreas, where a
  single dominant tube has gathered
  drainage from the surrounding area.
  Following uplift and the onset of vadose
  conditions any stream that utilizes the
  meandering tube incises rapidly and the
  imposed meander course is erxtrenched
  into the underlying rocks. Such incision
  or entrenchment produces characteristic
  tall, narrow, twisting vadose c|anyons, to
  such an extent that the French describe
  them as 'meandres'.  Canyons may
  meander more at their lower levels, due to
  enlargement during incision[9]l  2. A loop-
  like bend in a river due to lateral erosion
  activities1161.  3. hi a cave, an arcuate
  curve in a channel formed by lateral
  shifting of a cave stream[10].  See ceiling
  meander; meander niche.    [

meander belt.  A zone within which
  meandering of a stream occurs[16].

meandering karren. These are ;small
  grooves cut directly into the rock surface,
  generally a few centimeters wide and
  deep.  Their size remains the same or
  decreases downslope and usually exhibit
  small meanders with typical undercut
  slopes and slip-off slopes.  They
  frequently appear in the bottom of Larger
  grooves such as rinnenkarren1^. See also
                                           120

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  wall karren; humus-water grooves.
  Synonym: (German.) Mdanderkarren.., .;•

meander niche.  A conical or crescent--
  shaped opening in the wall of a cave,
  formed by the downward and lateral
  erosion of a stream on the floor of a
  passage001.

measuring flume.  An artificial channel
  used for discharge measurements.

measuring weir. A device used to measure
   flow rates indirectly through a weir head.

mechanical ascender. A mechanical device
   that is the same as an ascender, but is
   used to clarify the use of a mechanical
   device instead of a rope ascender knot[131.
   See also ascender.

mechanical cover.  A mechanical covering
   of a free water surface to prevent
   evaporation.

 mechanical dispersion. The process
   whereby solutes  are mechanically mixed
   during advective transport caused by the
   velocity variations at the microscopic
   level. Synonymous with hydraulic
   dispersion^221.

 mechanical dispersion, coefficient. The
   component of mass transport flux of
   solutes  caused by velocity variations at
   the microscopic level.  Synonymous with
   convective diffusion1221.

 median. A value dividing frequency of
   varieties into two equal portions1161.

 medicinal spring. See spring, medicinal.
medium sand.  Grain particle with a
  diameter of 0.25 to o.5 mm[16].

Meinzer unit. A measure of hydraulic
  conductivity as gpd/ft2 under a unit
  hydraulic gradient1161.

melanterite. A cave mineral —
  FeSCy7H20[11].

melting. The passage from the solid to the
   liquid state due to temperature
   increases1161.

melting point. The temperature at which a
   solid substance is transformed into its
   liquid state[161.

meltwater. Water derived from the melting
   of snow pack or of a glacier[16].

 meniscus. A free surface or interface
   formed by liquid in a capillary tube[16].

 mercury column.  A cylindrical bore in a
   manometer filled with mercury061.

 mercury injection method. A
   measurement of porosity by mercury
   injection into a sample[16].

 merokarst. 1. Defined by Cvijic to indicate
   imperfect karst topography as found on
   thin, impure, or chalky limestone where
   surface drainage and dry valleys are
   present in addition to some karstic fea-
   tures[10]. 2. Karst developed in soluble
   rocks retaining considerable surface
   drainage. Synonyms: (French.)
   merokarst; (Turkish.) yon karst.
    Contrast perfectly formed Holokarst.
    Compare causse.
                                             121
   consisting mainly of very fine particles of
   calcium and magnesium carbonate
   precipitated from water in caves and
   network or to a sinkhole plain1 3.
                                            125

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  and space1221. 3. A simplified system
  bearing some physical similarity to a
  prototypetl6].

model technique. A method of solving
moisture equivalent.  The percentage of
  water retained in a soil sample 1 cm thick
  after it has been saturated and
subjected
  to a centrifugal force 1000 times gravity
  for 30 min.  Centrifuge moisture
mud. Water saturated fine clayey earth
  material[16).

mud crack. Desiccation cracks appearing
  in drying mud surfaces due to
  shrinkage1161.

mud pendulite.  A pendulite with the knob
  coated in mud[25].

mud stalagmite.  1. Stalagmitic column
  made of mud or clay with about 30%
  calcium carbonate cement. There may be
  some coarse noncalcareous detritus in the
  core of such a column[201. 2. Stalagmite
  composed principally of clay or sandy
  clay and commonly less than 30%
  calcium carbonate[10]. Synonyms:
  (French.) stalagmite d'argile; (German.)
  Stalagmit aus Tonschlamm; (Greek.)
  pilostagmitis; (Italian.) stalagmite di
  fango; (Spanish.) ostalagmita de barro;
  (Turkish.) gamur dikiti. Related to
  stalagmite.

mudflow.  A flow of water saturated
  unconsolidated debris[I6].

multiaquifer formation. A formation with
  several aquifers overlying each other[16].

multiaquifer well.  A well completed and
  tapping several aquifers[16].

mutation. A sudden change in the genetic
  material of an organism's germ cells,
  resulting in offspring that possess
  characteristics markedly different from
  those of either parent.  Mutations
  generally are harmful, but occasionally
  may improve an organism's chances for
   survival1231. See also adaptation;
   evolution.
My. See Ma.
                                            126

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  wall karren; humus-water grooves.
  Synonym: (German.) Maanderkarren.  .

meander niche.  A conical or crescent--
  shaped opening in the wall of a cave,
  formed by the downward and lateral
  erosion of a stream on the  floor of a
  passage[10].

measuring flume.  An artificial channel
  used for discharge measurements.

measuring weir. A device used to measure
  flow rates indirectly through a weir head.

mechanical ascender.  A mechanical device
  that is the same as an ascender, but is
  used to clarify the use of a mechanical
  device instead of a rope ascender knot[13].
  See also ascender.

mechanical cover. A mechanical covering
  of a free water surface to prevent
  evaporation.

mechanical dispersion. The process
  whereby solutes are mechanically mixed
  during advective transport caused by the
  velocity variations at the microscopic
  level.  Synonymous with hydraulic
  dispersion1221.

mechanical dispersion, coefficient. The
  component of mass transport flux of
  solutes caused by velocity variations at
  the microscopic level. Synonymous with
  convective diffusion[22].

median. A value dividing frequency of
  varieties into two equal portionstl6].

medicinal spring. See spring, medicinal.
medium sand.  Grain particle with a
  diameter of 0.25 to o.5 mm[161.

Meinzer unit. A measure of hydraulic
  conductivity as gpd/ft2 under a unit
  hydraulic gradient[!6].

melanterite.  A cave mineral —
  FeSO4-7H20[11].

melting. The passage from the solid to the
  liquid state due to temperature
  increases^161.

melting point.  The temperature at which a
  solid substance is transformed into its
  liquid state[16].

meltwater. Water derived from the melting
  of snow pack or of a glacier[16].

meniscus.  A free surface or interface
  formed by liquid in a capillary tube[I6].

mercury column. A cylindrical bore in a
  manometer filled with mercury^.

mercury injection method. A
  measurement of porosity by mercury
  injection into a sample1161.

merokarst.  1. Defined by Cvijic to indicate
  imperfect karst topography as found on
  thin, impure, or chalky limestone where
  surface drainage and dry valleys are
  present in  addition to  some karstic fea-
  tures[10]. 2. Karst developed in soluble
  rocks retaining considerable surface
  drainage.  Synonyms: (French.)
  merokarst; (Turkish.) yan karst.
  Contrast perfectly formed Holokarst.
   Compare causse.
                                            121

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mesh.  1. An opening in a sieve screen[16]. 2.
  Number of openings per inch[16].

mesophyte.  A plant growing under
  intermediate moisture conditions[16].

metabolic rate.  The rate at which a living
  thing transforms food into energy and
  body tissue. The higher its metabolic
  rate, the more food it must consume.
  Most cave animals live at a reduced
  metabolic rate[23].

metabolism. The sum of the chemical
  activities taking place in the cells of a
  living thing; the sum of the processes by
  which a living thing transforms food into
  energy and living tissue[23].

metamorphosis. A change in the form of a
   living thing as it matures, especially the
   drastic transformation from a larva to an
   adult1233.  See also pupa.

meteoric water.  Water recently involved in
   atmospheric circulation[16].

meteorology. The science dealing with all
   physical phenomena occurring in the
   atmosphere1'61.

mexican onyx.  See onyx marble.

micrite.  A microscopic texture.  An
   abbreviation of 'microcrystalline calcite
   ooze' which refers to precipitated finely
   crystalline carbonate sediments in grains
   from 1 to 4 microns in diameter[201.
  . Synonyms: (French.) micrite; (Greek.)
   micrite; (Italian.) micrite; (Spanish.)
   micrita; (Turkish.) mikrit; (Yugoslavian.)
   mikrit. See biomicrite, peloid.
microclimate. "Little climate." The
  environmental conditions, such as
  temperature; humidity, and air movement,
  in a very restricted area, such as a
  sheltered nook in a cave wall[23].

microgour. Miniature rimstone dams with
  associated tiny pools of the order of 1cm
  wide and deep on flowstone[25];

microhabitat. A miniature habitat within a
  larger one; a restricted area where
  environmental conditions differ from
  those in the surrounding area. A sheltered
  nook in a cave wall is an example of a
  microhabitat within the cave[23l

microkarren. Very small dissolutional
   channels, commonly l-3mm across;
   parallel, convergent or randomly
   intersecting on a limestone surface.
   Though found in all climatic regions they
   are most conspicuous in semi-arid and
   periglacial environments, where
   dissolutional processes are minimal and
   very slow.  The random patterns of some
   microkarren may be due to the effects of
   condensation water[9].         \

 microkarst. 1. Karst area with small
   morphological features.  Term is not
   easily applied because it lacks' limits[20].
   2. Karst topography in which all surficial
   features are small; an area dominated by
   minor karst features[10]. Compare
   macrokarst.                 :

 microspar. A microscopic texture.  Mosaic
   of tiny (4 to 10 micron diameters) clear
   calcite crystal^01. Synonyms: (Trench.)
   microsparite; (Greek.) mikrosparitis
   (mikroskopikon, mosaikon kristdllon);
                                             122

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  (Italian.) microsparite; (Spanish.)
  microesparita; (Turkish.) mikrospar.

middens.  Accumulations of animal
  droppings other than guano and often
  found in caves; maybe solidified[13]. See
  also cave guano; guano cave; coprolite.

migration. The movement of water,
  contaminants, or other fluids in the
  geologic substratum, mostly by natural
  causes[16].

mine drainage. Waters coming from or
  passing through surface or subsurface
  mine workings[16].

mine water.  Water accumulating in a mine.

minerals. Mineral components of a rock,
  often in macrocrystalline form[16].

mineral spring. See spring, mineral.

mining of ground water.  The permanent
  depletion of ground-water reserves[16].

minor karst features.  See karren; rill;
  solution pan.

mirabilite. The natural white mineral form
  of hydrated sodium sulfate,
  Na2SO4-10H2O[9], which may grow as
  cave flowers or in various other forms
   similar to those of gypsum.

Mischungskorrosion.  (German.)
  Dissolution of calcite (and  hence of
   limestone) by ground water that is derived
   from the mixing of two different waters
   that were originally saturated with carbon
   dioxide but had reached saturation under
   differing carbon dioxide partial pressures.
  The resultant mixture is undersaturated
  and capable of further calcite dissolution,
  because the relationship between calcite
  solubility and carbon dioxide partial
  pressure is non-linear[9].

miscible.  1. Two or more liquids that are
  mutually soluble (i.e.  they will dissolve
  in each other[22].  2. The chemical property
  of two or more phases that, when brought
  together, have the ability to mix and form
  one phase[22].

miscible displacement.  1. The mutual
  mixing and movement of two fluids that
  are soluble in each other[22].  2. The
  displacement of a fluid saturating a
  porous medium by another fluid
  completely miscible with the first fluid[16].
  Synonymous with miscible-phase
  displacement.

mixing length. The length over which
  mixing occurs, especially of momentum
  in turbulent flow[16].

mixture corrosion.  See
  Mischungskorrosion.

mode. The most frequently occurring
  variate in a frequency distribution1163.

model. . 1. A conceptual, mathematical, or
  physical system obeying certain specified
  conditions, whose behavior is used to
  understand the physical system to which
  it is analogous in someway1221. 2. A
  conceptual description and the associated
  mathematical representation of a system,
  subsystem, components, or condition that
  is used to predict chances from a baseline
   state as a function of internal and/or
   external stimuli and as a function of time
                                            123

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  and space1221. 3. A simplified system
  bearing some physical similarity to a
  prototype1161.

model technique. A method of solving
  complex physical problems through the
  application of simplified models[16].

mogote.  A steep-sided hill of limestone,
  generally surrounded by nearly flat
  alluviated plains: karst inselberg. Orig-
  inally used in Cuba in referring to
  residual hills of folded limestone in the
  Sierra de los Organos but now used
  internationally for karst residual hills in
  the Tropics[10]. Differs from cone, cupola,
  pinnacle and tower karst in its shape
  which reflects its karstification history1201.
  Synonyms: (French.) mogote; (German.)
  (Karstinselberg), Mogote; (Greek.)
   'moghotis' (apokrimnos, asvestolofos
  perikliomenos apo proschomatikas
  pediadas); (Italian.) mogote,  rilievo
   carsico residue; (Spanish.) mogote;
   (Turkish.) karst kalmti tepesi;
   (Yugoslavian.) hum.  See also hum; karst
   inselberg; pepino hill.

 moisture content.-1. The ratio; expressed
   as a'percentage, of either (a)  the weight of
   water to the weight of solid particles
   expressed as moisture weight percentage
   or (b) the volume of water to the volume
   of solid particles expressed as moisture
   volume percentage in a given volume of
   porous medium1221. 2. The gravimetric
   water vapor content of air[16]. See also
   water content.

 moisture deficiency. The quantity of water
   required to restore moisture to field
   capacity in a desiccated soil[16].
moisture equivalent.  The percentage of
  water retained in a soil sample 1 cm thick
  after it has been saturated and subjected
  to a centrifugal force 1000 times gravity
  for 30 min.  Centrifuge moisture
  equivalent is the water content I of a soil
  after it has been saturated with: water and
  then subjected for 1 hour to a force equal
  to 1000 times that of gravity1221.

moisture tension. The equivalent negative
  pressure of water in an unsatajated porous
  medium equal to the pressure that must be
  applied to the medium to bring the water
  to hydraulic equilibrium through a porous
  permeable material with a pool of water
  of the same composition.  Synonym:
  capillary tension1221.          '

moisture volume percentage. The ratio of
  the volume of water in a soil to  the total
  bulk volume of the soil[22].   ;
                              1

moisture weight percentage.  The moisture
   content expressed as a percentage of the
   oven-dry weight of a soil[221.  '-.
                              i
mold. A microscopic form of fungus
   responsible for much food spoilage and,
   in caves, for conspicuous tufts quickly
   covering scats, dead insects arid bats, and
   even wooden structures such as
   ladders[23].

molecular diffusion (diffusion.) The
   process whereby solutes are transported at
   the microscopic level due to variations in
   the solute concentrations within the fluid
   phases[22]. The kinetic energyigenerated
   by the transport of ionic or molecular
   constituents results in some dispersion of
   a chemical.
                                             124

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molecular diffusion, coefficient of.  The
  component of mass transport flux of
  solutes (at the microscopic level) due to
  variations in solute concentrations within
  the fluid phases. Synonymous with
  diffusion coefficient1223.

molecule. A stable configuration of atomic
  nuclei and electrons bound together by
  electrostatic and electromagnetic forces.
  It is the simplest structural unit that
  displays the characteristic physical and
  chemical properties of a compound[6].

mollisol. A soil layer subject annual
  thawing and freezing, often becoming
  mobile upon thawing[16].

monetite. A cave mineral — CaHPO4[11].

monohydrocalcite. A cave mineral —
  CaCO3-H2O[11].

monomolecular film. A layer of
  monomolecular thickness of a polar
   substance spread over a free water surface
   to prevent evaporation.

montgomeryite. A cave mineral —
   Ca4MgAl4(P04)6(OH)4-12H20[11].

montmorillonite.  A clay mineral
   containing magnesium oxide (MgO) in its
   structure1161.

moonmilk.  1. A white plastic calcareous
   cave deposit composed of calcite, huntite,
   or magnesite. From Swiss dialect moon-
   milch, elf s milk.  Corrupt spelling
   mondmilch is common[10].  2. Deposits
   consisting mainly of very fine particles of
   calcium and magnesium carbonate
   precipitated from water in caves and
  caverns.  When in suspension, they give
  the water the appearance of milk. Name
  originated in 1714 by M. B. Valentini
  (Fenelon)[20]. 3. Moonmilk consists of a
  variety of hydrocarbonates some of which
  are associated with particular species of
  bacteria.  A common mineral in
  moonmilk from temperate caves is
  hydromagnesite; cold caves yield
  moonmilk of calcite after hydrocalcite[20].
  Synonyms: (French.) mondmilch;
  (German.) Bergmilch, Montmilch;
  (Greek.)  speleogala; (Italian.) latte di
  monte; (Russian.) kamennce moloko;
  (Spanish.) mondmilch, leche de luna;
  (Turkish.) dik karstik kahnti;
  (Yugoslavian.) gorsko mlijeko (mleko).
  Also mountain milk.

moor. A wet peat bog[16].

moulin. The French word for 'mil', moulin
  has been used to describe partially
  dissolutional, partially scoured pockets
  cut in rock, particularly the potholes
  formed in the beds of surface and
  underground streams.  In some areas
  sinkholes in the surface of glaciers, which
  may provide access to glacier caves, are
  also referred to as moulins[9].

mountain milk. See moonmilk.

moraine. A mound, ridge, or other distinct
  accumulation of unsorted, unstratified
  glacial drift, predominantly till, deposited
  chiefly by direct action of glacier ice[6].

morphometric analysis.  A geodetic and
  geometric description of basin and stream
  network or to a sinkhole plain[16].
                                            125

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mud. Water saturated fine clayey earth
  material[16J.

mud crack. Desiccation cracks appearing
  in drying mud surfaces due to
  shrinkage1161.

mud pendulite.  A pendulite with the knob
  coated in mud[25].

mud stalagmite.  1. Stalagmitic column
  made of mud or clay with about 30%
  calcium carbonate cement.  There may be
  some coarse noncalcareous detritus in the
  core of such a column[20]. 2. Stalagmite
  composed principally of clay or sandy
  clay and commonly less than 30%
  calcium carbonate[10]. Synonyms:
  (French.) stalagmite d'argile; (German.)
  Stalagmit ans Tonschlamm; (Greek.)
  pilostagmitis; (Italian.) stalagmite di
  fango; (Spanish.) ostalagmita de barro;
  (Turkish.) gamiir dikiti. Related to
  stalagmite.

mudflow.  A flow of water saturated
  unconsolidated debris[16].

multiaquifer formation. A formation with
   several aquifers overlying each other[16].

multiaquifer well.  A well completed and
  tapping several aquifers[I(51.

mutation. A sudden change in the genetic
  material of an organism's germ cells,
   resulting hi offspring that possess
   characteristics markedly different from
   those of either parent. Mutations
   generally are harmful, but occasionally
   may improve an organism's chances for
   survival231. See also adaptation;
   evolution.
My. See Ma.
                                            126

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                   N
Nackter karst. (German.) See exposed
  karst.

Nacktkarst.  (German.) See exposed karst.

naked karst, bare karst. Karst topography
  developed beneath a temporary cover.
  Some naked karsts develop beneath a
  temporary cover of snow (nival karst) or
  water[17].  Synonyms: (French.) karst nu;
  (German.) oberfldchlicher nackter Karst;
  (Greek.) gymnon karst; (Italian.) carso
  nudo; (Russian.) golyl karst or otkrytyl
  karst; (Spanish.) karst desnudo;
  (Turkish.) ciplak karst; (Yugoslavian.)
  goli krs. See also exposed karst.

NAPL. Abbreviation for nonaqueous phase
  liquid.  This term is used to describe the
  physico- chemical that exist between a
  bulk hydrocarbon and water which results
  in the two liquids being immiscible with
  one another (i.e. little or no mixing of the
  two liquids occurs.)  The interface is a
  physical dividing surface between the
  bulk phases of the two liquids. NAPLs
   are divided into two categories; LNAPLs
   andDNAPLs.  See also DNAPL;
   immiscible; LNAPL.

nari. Term used in the countries bordering
   the Eastern Mediterranean for caliche or
  . hardpan[20]. See caliche, sabath.

narrow. A passage of restricted width
   between two caves or hollows in the karst
   underground; often not readily
   traversable[20].  Synonyms: (French.)
   etroiture; (German.) Enge; (Greek.) steno
  perasma; (Italian.) strettoia; (Russian.)
   laz; (Spanish.) laminador, gatera;
  (Turkish.) agiz gecit; (Yugoslavian.)
  sutjeska, klisura, soteska.

native ground water. Original ground
  water^.

natural arch. 1. A residual portion of the
  roof of a subsurface karst cavity which
  has not collapsed.  Such a natural arch
  may occur as a surface topographic
  feature, or as apart of a cave; system1203.
  2. A rock arch or very short natural
  tunnel; contrasted with natural bridge,
  which spans a ravine or valley[10].
  Synonyms: (French.) arche naturelle;
  (German.) naturlisches Gewolbe,
  Naturbrucke, Felsfenster, Felsbriicke;
  (Greek.) physike apsitha; (Italian.) area
  naturale; (Russian.) estestvennij arka;
  (Spanish.) arco natural; (Turkish.) dogal
  kemer; (Yugoslavian.) prirodni svod, luk,
  naravni obok. See also natural bridge.

natural bridge. 1. A residual portion of the
  roof of a subterranean stream which has
  not collapsed and is found bridging a
  valley. Normally a surface feature, but
  may be used to describe a similar
  occurrence in a cave system[20]. 2. A rock
  bridge spanning a ravine and not yet
  eroded away[10]. Synonyms: (French.)
  pont naturel; (German.) Naturbrucke,
  Felsbriicke; (Greek.) physiki gejyra;
  (Italian.) ponte naturale; (Russian.)
  estestvennij most;  (Spanish.) puente
  natural; (Turkish.) dogal kopru;
  (Yugoslavian.) prirodni most,  naravni
  most.  See also natural arch.

natural levee.  A river bank raised by the
  river's own depositions1161.
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natural load.  Sediment carried by a stable
   stream1161.

natural tunnel.  A nearly horizontal cave
   open at both ends, generally fairly straight
   in direction and fairly uniform in cross
   section1101.

natural water. Water with a mineral
   content occurring under natural
   conditions.

natural well.  (Jamaican.) A vertical shaft
   in limestone, open to the surface and
   having water at the bottom; similar to  a
   cenote[l°]. Synonym: (Italian.) pozzo
   carsico.

neck. A volcanic pipe filled with lava[16].

necrophage.  A scavenger feeding on
   animal carcasses (not prey)[25].

neomorphism. A microscopic texture. A
   complex of processes whereby a mosaic
   of finely crystalline carbonate is replaced
   by a coarser (sparry) mosaic without the
   development of visible porosity.
   Dominant reactions are the wet
   transformation of aragonite to calcite and
   recrystallization. The process is
   'porphyroid' where some of the
   neomorphic crystals are conspicuously
   larger than those which surround them[20].
   Synonyms:  (French.) neomorphisme;
   (German.) Neomorphismus ?; (Greek.)
   neomorphismos; (Spanish.) neomorfismo;
   (Turkish.) neomorfizm.

neoteny. The condition of retaining larval
   form and behavior even as a mature
   individual.  Certain salamanders in
   particular are neotenic[23].
neptunian deposits. Younger sediment or
  sedimentary rock that infills pre-existing
  cavities, such as grikes, dolines or cave
  passages, in older rocks. The most
  common form is a fissure fill, known as a
  neptunian dike. Neptunian deposits
  occupy voids in non-karstic as well as
  karstic rocks, and the combination of void
  and fill may subsequently be buried by
  still younger rocks. They may thus
  become part of a paleokarst[9].

nesquehonite. A cave mineral —
  Mg(HCO3)(OH)-2H2O[11].
                              l
nested sinkholes. (American.) See uvala.

net radiation. The sum of incident and
  reflected sun and sky shortwaye radiation
  plus incident and reflected atmospheric
  long-wave radiation[16].

network cave pattern. A type of maze
  cave characterized by a complex pattern
  of repeatedly connected passages in a
  cave system. In map view, this type of
  maze cave appears similar to aj city street
  map. It is typically formed by 1
  solutionally aggressive water infiltrating
  through fractures in an overlying
  insoluble cap-rock thus exhibiting a joint-
  controlled pattern. Synonym: labyrinth.

neutrality point. The separation point
  between acid and basic solution with a/?H
neuromast. One of the individual sense
   organs that make up the lateral line
   systems of fishes and amphibians[23].  See
   also cupula.
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nife cell. A rechargeable alkaline battery for
  use with an electric-cap lamp[25].
                                     W'
nip. An undercutting notch in rock,
  particularly limestone, along a seacoast
  between high and low tide levels along
  sea coasts and produced by solution and
  erosion. Most common along coasts with
  limited tidal variation[20]. Synonyms:
  (French.) resserrement, etranglement;
  (German.) Kliff?, Brandungsmarke;
  (Greek.) kdto engopi vrdchou; (Italian.)
  solco di battigia; (Spanish.) socavacion
  marina; (Turkish.) dalga yangi fentigi.

nfaa. See aisle.

niter.  A white orthorhombic mineral —
   KNO3. It is a soluble crystalline salt that
   occurs as a product of nitrification in
   most arable soils in hot, dry regions, and
   in the loose earth forming the floors of
   some natural cavesm. Synonyms:
   saltpeter; potassium nitrate.

 nitrammite. A cave mineral — NH4NO3[11].

 nitrocalcite. A cave mineral —
   Ca(NO3)2-4H2Otll].

 nitromagnesite.  A cave mineral —
   Mg(N03)2-6H2O[11].

 nival karst.  Alpine karst[1].

 nivo-karst.  A karst-like topography
    produced by the differential chemical
    weathering beneath snowbanks from
    snowmelt containing carbonic acid. It is
    found mostly in periglacial areas[1].

 node point. The intersection point on a
    grid^.
nodule. A small, irregularly rounded knot,
  mass, or lump of a mineral or mineral
  aggregate, normally having a warty or
  knobby surface and no internal structure,
  and usually exhibiting a contrasting
  composition from the enclosing sediment
  or rock matrix in which it is embedded
  (e.g. a chert nodule in limestone.) Most
  nodules appear to be secondary structures
  in sedimentary rocks they are primarily
  the result of post depositional
  replacement of the rock and are
  commonly elongated parallel to the
  bedding.  Nodules can be separated as
  discrete masses from the host material[1].

noethphreatic flow. A type of conduit flow
  that is always laminar19'.

nominal. Used to describe standard sizes
   for pipe from V8 inch to 12 inches (3.2
   mm to 304 mm.) The nominal size is
   specified on the basis of the inside
   diameter.  Depending on the wall
   thickness, the inside diameter maybe less
   than or greater than the number
   indicated161.

 nongraded. An engineering term pertaining
   to a soil or an unconsolidated sediment
   consisting of particles of essentially the
   same size[6].

 non-point source.  1. Any source, other
   than a point source, which discharges
   pollutants into air or water[22]. 2. Source
   originating over broad areas, such as areas
   of fertilizer and pesticide application and
   leaking sewer systems, rather than from
   discrete points[22].

 non-recording gage.  A standard rain gage
   (8 is standard in U.S.)[16].
                                             129

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normal depth. The depth at which uniform
  flow occurs in an open channel^61.

normal fault. A fault in which the upper
  block appears to have moved downward
  relative to the lower block.

Northing. 1. The distance of a point north
  of the point of origin of the grid of a map,
  or some abbreviation of it. 2. The
  south-north component of a survey leg, or
  of a series of legs, or of a complete
  traverse; north is positive and south is
  negative1251.

nothephreatic. Referring to water moving
  slowly in cavities in the phreatic zone[25].

numbering. Assigning an alphanumeric
  index to a cave entrance'251.
                                           130

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                   o
oasis. A limited area in a desert supplied
  with water1161.

obruk.  Turkish form for a vertical or
  steepsided depression or shaft in karst,
  often formed by collapse of roof of an
  underground cave or cavern.  When the
  depression contains a lake of pond, it is
  known as 'sulu obruk' or 'obruk go'lii'.
  When it is dry, it is called 'kuru obruk' or
  just 'obruk'.  Synonyms: (French.) obruk;
  (German.) Schlot; (Greek.) 'obruk'
   (kdthetos karstikos Idkkos); (Italian.)
  pozzo carsico; (Spanish.) torca;
   (Turkish.) obruk; (Yugoslavian.) jama.
   See cenote, dolina, jama, pit, shaft,
   sinkhole.

 obsequent river. A river flowing in a
   direction opposite to that of the dip of the
   underlying strata[16].

 observation well.  A well drilled for the
   purpose of observations such as water
   level or pressure recordings1161.

 oceanic water. Sea water with a total salt
   content of about 34,500 ppm[16].

 ojo, ojo de agua. (Spanish.) An artesian
   spring in limestone regions, especially
   one forming a small pond; a vauclusian
   spring.

 olivenite. A cave mineral —
   Cu2(As04)(OH)[11].

 omnivore. An animal that habitually eats
   both plants and animals[23]. See also
    carnivore; herbivore; insectivore.
onyx marble. Translucent layers of calcium
  carbonate from cave deposits, often called
  Mexican onyx or cave onyx; used as an
  ornamental stone[10].

oolite. A type of limestone that is composed
  largely or partly of eoliths. Also known
  as oolitic limestone. The best known
  examples in Britain, within the Jurassic
  limestone sequence of the Cotswolds, are
  of only moderate strength, very porous
  and only weakly cavernous. In contrast,
  oolites of early Carboniferous age have
  hosted extensive cave development
  beneath Mymydd Llangattwg and in other
  parts of South Wales[9].

 oolith. A small ovoid to spherical
   accretionary particle, usually composed of
   concentric layers of calcium carbonate.
   Such ooliths, cemented together by
   calcium carbonate, iron salts or other
   minerals, are the major constituent of
   oolite or oolitic limestone191.

 oolitic. Of spherical or ovoidal shape[161.

 opal.  A cave mineral —  SiCy«H2O[111.

 open system.  A system where matter and
   energy may cross a system boundary1161.

 open traverse. A traverse which does not
   close onto a survey point of known
   coordinates and orientation or onto
   itselfl251.

 Opferkessel.  See solution pan.

 optical brighteners.  Material contained in
    laundry detergents to make 'whites
    whiter' and used in environmental tracing
    studies. Common types are, Tinopal
                                             131

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   CBS-X, Tinopal 5BM GX, and Phorwite
   BBHPure. Dye type: Stilbene. See also
   fluorescent dyes.

ore karst.  Formation of interstices, caverns
   caves and other karst forms produced by
   solution in water from thermal springs
   and ore-bearing solutions1201.  Synonyms:
   (French.) karst minier; (German.)
   Zwischenraume, Kavernen, Hohlen im
   Karst, gebildet durch Thermalwasser
   oder erzhaltige Losungen; (Greek.)
   thermometallikon karst; (Italian.)
   carsismoper dissoluzione idrotermale;
   (Russian.) rudnij karst; (Spanish.) karst
   termomineral; (Turkish.) cevher karsti;
   (Yugoslavian.) rudni krs(kras).

organic. Pertaining to anything that is or
   ever was alive or produced by a living
   plant or animal. Organic material brought
   into the cave from outside is virtually the
   only source of food for cave dwellers[23].

organic deposit. Deposits of calcareous and
   siliceous remains of animals[I6].

organic pollution. Contamination
   originating from organic sources[16].

orientation.  1. The assignment or
   imposition of a definite direction in
   space; the act of establishing the correct
   relationship in direction, usually with
   reference to the points of the compass.
   Also, the of being in such relationship.  2.
   In describing crystal form and symmetry,
   the placing of the crystal so that its
   crystallographic axes are in the
   conventional position. 3. The direction
   in which an aerial photograph is turned
   with respect to observer or map.  A single
   photo is best oriented for study when
   turned so that the shadows are cast toward
   the observer.  4. Directional arrangement
   of nonspherical grains in a sarid
   aggregate[16].                :

original dip. Dip due to deposition of
   sediments[16].                j
                              !
original interstice. Interstice formed during
   rock formation stage[16].      ;

orographic precipitation.  Precipitation
   due to mechanical lifting of ai|r over a
   ground relief1163.             \

orthogonal. Perpendicular.

otkryi karst. (Russian.) See naked karst.

oulopholite.  See cave flower.

outcrop.  An open exposure of bedrock or
   otherwise buried material1161.
                              i
outflow cave. Cave from which!stream
   flows out or formerly did so[10].
   Synonym: effluent cave.

outlet cave. A cave developed a|t the point
   of re-emergence of an underground karst
   watercourse[I9].              I

output point. A point where water exists
   from an underground  drainage route or
   aquifer. An obvious output point is a
   surface resurgence or  exsurgence, where
   drainage emerges from a conduit system.
   Less obvious are points where; drainage
   leaves a carbonate aquifer and; enters an
   adjacent non-carbonate bed, such as a
   sandstone aquifer[9].
                              i
outwash.  Stratified sand and gravel
   removed or washed out from a glacier by
                                            132

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  meltwater streams and deposited in front
  of or beyond the end moraine or the
  margin of an active glacier. The coarser
  material is deposited nearer to the ice[6].

outwash gravel. Glacial drift material
  deposited by streams from a glacier[16].

outwash plain. Plain in front of a glacier
  that is composed of outwash material1161.
  A broad, gently sloping sheet of
  outwash[61.
oxbow. Abandoned loop of a stream course,
  Original usage, applied to surface rivers,
  describes short-circuited meander loops
  but in caves the term is applied to dry
  loop passages of any shape and origin[9].

oxidation. The combining of an element
  with oxygen[6].

oxygen demand.  The ability of substances
  to utilize dissolved oxygen in water.
ouvala. (French.) See uvala.

oven-dry. The degree of dryness of a
  •porous sample after drying in an oven at a
   specified temperature[16].

overbank area. An area covered by flood
   waters overtopping natural or artificial
   river banks1161.

overburden. 1. The loose soil, sand, silt, or
   clay that overlies bedrock. In some
   usages it refers to all material overlying
   the point of interest. 2. The total cover of
   soil and rock overlying an underground
   excavation.

overburden pressure. The pressure exerted
   by weight of the overburden column[16].

overflow spring.  See spring, overflow.

overland flow. Surface runoff flowing over
   the land surface towards a channel[16].

overthrust.  Upthrust fault with a very low
   angle of dip and a relatively large net
   displacement^61.
                                            133

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 packing. The three-dimensional
   arrangement of particles[I6].

 pahoehoe.  (Hawaiian.) Lava flows with a
   smooth or billowy surface in which lava
   tubes are found[13]. See also lava cave;
   pseudokarst.

 paleokarst.  1. A karstified rock or area that
   has been buried by later sediments; in
   some places, ancient caves have been
   completely filled by the later
   sediments1101. 2. A decoupled
   contemporary system that has
   experienced tectonic subsidence and lie
   unconformably beneath clastic cover
   rocks, occasionally becoming exhumed
   and re-integrated into the active
   system[17]. 3.  A karst formed in the past
   under an earlier erosion cycle and often in
   remote geological times. The karst is
   preserved by burial or suspension of
   karstification processes1201. 4. A karstified
   surface and the karst features associated
   with it, such as'caves, that have been
   buried by younger rocks. Paleokarstic
   features at various scales may be
   recognized within most carbonate
   successions. More rarely they may be re-
   exposed (exhumed) by the effects of later
   uplift and erosion[9]. Synonyms: (French.)
  paleokarst; (German.) Paldokarst,
  fofiiler Karst; (Greek.) paleokarst;
   (Italian.) paleocarsismo, carsismo
  fossile; (Russian.) paleokarst; (Spanish.)
  paleokarst; (Turkish.) eski karst;
   (Yugoslavian.) paleokrs, paleokras,
  paleokarst. See also buried karst.

paleokarstic surface. A surface, preserved
  within a carbonate succession, that was
   formed by the effects of karst erosion.
   The presence of a paleokarstic surface
   indicates that during the deposition of the
   full rock sequence the young rocks were
   exposed to the effects of surface (sub-
   aerial) erosion. During such a non-
   depositional and erosional phase a full
   suite of karst features, including caves,
   could develop191.            \

 paleomagnetism. Natural remahent
   magnetization preserved in ro;ck
   sequences. During rock deposition
   magnetic minerals are aligned according
   to the direction and polarity of the earth's
   contemporary magnetic field.: After
   movement of the magnetic poles, or
   periodic reversals of polarity, the
   remanent magnetization is preserved in
   the rocks and may be measured to aid
   identification of stratigraphical units and
   to assess their relative ages[9]. •

 paleontology. The study of life in past
   geologic time, based fossil plants arid
   animals and including phylogeny, their
   relationships to existing plants, animals,
   and environments, and the chronology of
   the Earth's history111.

 palette,  hi a cave, a more or less flat
   protruding sheet of crystalline calcium
   carbonate spared during solution of the
   rock on each side of it[10].  See also blade;
   shield. Synonym: shield.

palygorskite. A cave mineral—
   (Mg,Al)2Si4010(OH)-4H20[ni.;

pan  coefficient. Coefficient to correlate a
   high rate of evaporation in a pan to an
   evaporation rate from larger water
   bodies1161.
                                            134

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panhole. See solution pan.             .:->•

paragenesis. A type of cave passage
   development in which erosion of the
   passage floor is inhibited by the presence
   of an armoring layer of sediment, such
   that any dissolutional enlargement is
   dominantly upwards191.  Generally, an
   unproven and unsupported theory.

paragenetic cave. Cave passage, usually of
   canyon form, believed to be created by
   paragenesis.  Passage formation by
   paragenesis is normally very difficult to
   prove, as later sediment removal leaves a
   passage that looks very similar to the far
   more common vadose canyon.  It is
   thought that some of the larger canyons in
   the Flint Mammoth Cave System, USA,
   may have formed in this way191.

 parahopeite.  A cave mineral —
   Zn3(P04)2-4H20[11].

 paraphreatic.  A paraphreatic passage has
   an air surface under relatively low flow
   conditions, when drainage is within the
   capacity of its downstream continuation,
   but reverts to being water-filled (phreatic)
   under conditions of high flow or when the
   downstream drainage is temporarily
   impeded191.

 parent material.  Material from which soil
   or sediment was formed[161.

 parietal fauna. Pertaining to the
   inhabitants on the walls of the  entrance
   and twilight zones of a cave[23].

 park.  (Arizona.) Shallow broad solution
    depression1101.
particle.. The smallest individual
  constituent of an aggregate1161.

particulate transport.  The movement of
  particles in subsurface water[22].

parting. The separation of sedimentary
  rock along bedding planes[16]. Synonyms:
  bedding-plane; bedding-plane parting.
   See also bedding plane.

partition. 1. A nearly vertical residual rock
   mass in a cave. 2. A continuous rock
   span across a cave[10].

partitioning function. A mathematical
   relation describing the distribution of a
   reactive solute between solution and other
   phases[22].

parts per million. An expression of
   concentration (ppm.) The weight per
   weieht of a solution1161.
UUil^ciiua.i.iija.4. \jjpuu.) J.i
weight of a solution1161.
 passage. 1. Broadly, a passage is any
   negotiable part of cave system, though the
   usage is commonly restricted to those
   elements that tend towards the horizontal
   rather than vertical or sub-vertical
   sections.  Cave passages very in size and
   shape, with the latter relating to the mode
   of origin and providing evidence of the
   nature of cave development mechanisms.
   Perhaps the largest passage in the world is
   Deer Cave, which is up to 170m wide and
    120m high, in the Mulu karst of
    Sarawak[91. 2. A comparatively small
    underground opening made along
    fractures, fissures, and bedding-plane
   .partings by running water but through
    which it is possible to pass[20]. 3. hi a
    cave, the opening between rooms or
    chambers[10]. Synonyms: (French.)
                                             135

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   galerie; (German.) Gallerie, Stollen;
   (Greek.) ypohios ihiofhos; (Italian.)
   cunicolo, galleria; (Russian.) hod;
   (Spanish.) galeria; (Turkish.) gegit;
   (Yugoslavian.) galerija. See also
   chamber; room.

pathogenic bacteria. Disease inducing
   bacteria[I6].

pavement.  See limestone pavement.

peat. Decomposed matter, mainly
   vegetable1161.

pebble. A smooth rounded rock
   fragment1161.

Pdclet number. 1. measure of the relative
   contribution of mechanical dispersion and
   diffusion to solute transport. It relates the
   effectiveness of mass transport by
   advection **-^~T-HS/I-—* t
   effectiveness of mass transport by either
   dispersion or diffusion IP, a 4^. Peclet
     r                  *   tx2 t,
   numbers below =0.4 indicate
   diffusion/dispersion control; 0.4-6.0
   suggest that diffusion/dispersion and
   advection are in transition and thus
   approximately equal to each other; and
   >6.0 indicate advection control.  Large
   Peclet numbers indicate strongly
   advective systems.  2. A relationship
   between the advective and diffusive
   components of solute transport expressed
   as the ratio of the product of the average
   interstitial velocity, times the
   characteristic length, divided by the
   coefficient of molecular diffusion. Small
   values indicate diffusion dominance,
   large values indicate advection
   dominance1221.
pearl. See cave pearl.

pediment. An inclined erosion jsurface
   covered with thin fluvial deppsits[I6].

pendulite. A kind of stalactite ^hich has
   been partly submerged1251.    !

and the submerged part covered jwith
dog-tooth spar to give the appearance of a
drumstick.                    i
                              i
pellicular water.  1. The film of water left
   around each grain or fracture surface of
   water-bearing material after gravity
   drainage[22].  2. Water of-adhesion[22].  3.
   Water that can be extracted by root
   absorption and evaporation but cannot be
   moved by gravity or by the unbalanced
   film forces resulting from localized
   evaporation and transpiration1221.
                              i

peloid. A microscopic texture. A
   sedimentary grain composed of micrite
   carbonate irrespective of origin[20].
   Synonyms:  (French.) peloi'de; \(German.)
   mikroskopisches, sedimentdres Gefuge;
   (Greek.) piloidis; (Italian.) pelpide;
   (Spanish.) peloide; (Turkish.) \peloit.
   See micrite, pelsparite.       !
                              i
pelsparite. A microscopic texture.  A
   limestone composed of pellets (peloids)
   in a matrix of cement[20]. Synonyms:
   (French.) pelsparite; (GermanJ.)
   Pelsarite, Kalkstein gefugt aus
   Kugelchen ?; (Greek.) pelspamtis;
   (Italian.) pelsparite; (Spanish.)
  pelsparita; (Turkish.) pelsparit.  See
   peloids.                     i

pendant, rock pendant. One of a group of
   isolated similarly proportioned
                                            136

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  projections surrounded by a complex of
  connected cavities in the bedrock ceiling  :
  ofacave[10]. Formed by the rapid,
  differential solution of the surrounding
  rockt191.

pendular regime.' A saturation regime
  where a porous medium has the lowest
  possible saturation in the form of
  pendular rings at grain contacts1161.

peneplain. A degradation surface without
  relief161.

pen trace.  Ink, magnetic, or photographic
  line traced on the drum of a recording
  gage or meter[161.

pepino hill. (Puerto Rican.) 1. Rounded or
   conical-shaped hill resulting from tropical
  humid karst action. Term generally
   replaced in Puerto Rico by mogote.  2.
   Elongate hill or ridge capped by
   mogotes[10]. See mogote.

percent saturation. The ratio, expressed as
   a percentage, of (a) the volume of some
   fluid (water, gas, or oil) to (b) the total
   volume of intergranular space (voids) in a
   given porous medium. Synonymous with
   degree of saturation1221.

 perched ground water. Ground water
   separated from an underlying body of
   ground water by an unsaturated zone[6].
   See also ground water, perched.

 perched karst spring.  See spring, perched
   karst.

 perched water table. Unconfmed ground
    water separated from an underlying body
    of ground water by unsaturated soil or
  rock, ft may be either temporary or
  permanent.

percolate. To flow through saturated void
  space[16]. The act of water seeping or
  filtering through soil or rock without a
  definite channel[6].

percolation; percolation water. 1. Ground
  water moving slowly through the micro-
  fissure network of a limestone, most of
  which eventually joins a major cave
  conduit and flows more rapidly. In most
  environments percolation water enters the
  limestone through a soil cover.  It is
  therefore high in carbon dioxide and has a
  major influence on  limestone dissolution
   and later redeposition of calcite
   speleothems. Percolation water accounts
   for most of the storage in a limestone
   aquifer, responds slowly to flooding in
   comparison to sinkhole water, and is
   normally of high enough quality to
   provide a drinking-water supply191. 2. The
   movement in laminar flow under
   hydrostatic pressure of water through the
   interconnected, saturated interstices of
   rock or soil, excluding movement through
   large openings such as caves and solution
   channels.  3. The downward movement of
   water through the unsaturated zone[22]. 4.
   The downward flow of water in saturated
   or nearly saturated porous medium at
   hydraulic gradients of the order of 1.0 or
   less[221.  5. The movement of water
   through saturated interior pore space[16].
   Synonym: seepage water.   :

 percolation water. Autochthonous karst
   water which permeates directly through
   karst limestone without using a surface
   watercourse[19].
                                             137

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perennial spring.  See spring, perennial.

perennial yield. Sustained yield[16].

periodic spring, see spring, periodic.

perforation.  Holes or openings in well
   casing to permit water inflow into a
   well!16'.

permafrost.  Ground that is perennially
   below the freezing point of water[16].

permafrost karst. A nonkarst term. A
   pseudokarst developed in areas of
   permafrost due to melting of ice and
   frozen ground in a manner superficially
   similar to the solution of carbonate
   material in water. A general term
   embracing intrapermafrost karst,
   subpermafrost karst, and suprapermafrost
   karst[20]. (French.) karst de permafrost;
   (German.)  Permafrost Karst ?,
   Pseudokarst; (Greek.) karst monimou
   paghtoii', (Italian.) pseudo-carsismo di
   permafrost; (Spanish.) karst de
   permafrost; (Turkish.) aldatici don
   karsti; (Yugoslavian.} permafrost kfs
   (kras, karst).

permafrost table. The upper limit of
   permafrost[16].

permanent hardness.  Noncarbonate
   hardness[16].

permanent wilting point. Saturation at
   which permanent wilting occurs[16].

permeability.  See hydraulic conductivity;
   permeability, intrinsic.
permeability barrier. See barrier,
  permeability.

permeability coefficient.  The rate of flow
  of water through a unit cross-sectional
  area under a unit hydraulic gradient at the
  prevailing temperature (field permeability
  coefficient) or adjusted to a temperature
  of!5oC[22].                 !
                             i
                             i
permeability, effective. The observed
  permeability of a porous medium to one
  fluid phase under conditions of physical
  interaction between this phase and other
  fluid phases present[22].      !

permeability, intrinsic. 1. A measure of
  the ability of a medium to transmit a fluid
  through a porous medium. It is a function
  of the medium only and is proportional to
  the mean grain size diameter.', 2. A
  measure of the relative ease with which a
  porous medium can transmit a fluid under
  a potential gradient and is a property of
  the medium alone[22].  3. The property of a
  porous medium itself that expresses the
  ease with which gases, liquids, or other
  substances can pass through it[22].
                             I
permeability, relative.  1. The ratio of the
  effective permeability for a given flow
  phase to the intrinsic permeability of the
  porous medium[22]. 2. The ratjo of the
  effective and specific permeabilities1221.
  3; The ratio of permeability of one
  immiscible phase to intrinsic permeability
  in multiphase flow[16].

permeability, specific. The permeability
  measured when the rock contains only
  one fluid[22].                !
                                            138

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permeability tensor.  Permeability In an
   anisotropic medium1161.               ?»

permeability, transverse. Permeability
   measured perpendicular to the axis of a
   core sample[161.

permeameter.  A device used to measure
   the permeability of small-samples1163.
                                [16]
pervious. Permitting fluids to pass1
petrography. The science of describing and
   identifying rocks[16].

pH. A measure of the acidity or alkalinity of
   a solution, numerically equal to 7 "for
   neutral solutions, increasing with
   increasing alkalinity and decreasing with
   increasing acidity.  Originally stood for
   the words, potential of hydrogen[6].

 phonolite.  A type of volcanic rock,
   common as lava flows in some areas, that
   is capable of supporting the formation of
   extensive lava caves, including those on
   Mount Suswa in Kenya191.

 photogeology. The interpretation of aerial
   photographs for geological purposes[16].

 photogrammetry. The preparation of maps
    and measurements from stereoscopic
    aerial photographs1161.

 photosynthesis. The process by which
    green plants convert carbon dioxide and
    water into simple sugar.  Chlorophyll and
    sunlight are essential to the series of
    complex chemical reactions involved in
    the process[23].
phreas, phreatic water.  (From the Greek
  word meaning well.) 1. The zone of
  saturated rock below the water table,
  within which all conduits and sub-
  conduits are water filled (sometimes
  referred to as the flooded, phreatic or
  saturated zone). Commonly the phreatic
  zone is considered as being subdivided
  into an upper (shallow phreatic) zone and
  a lower stagnant phreatic zone[9].  2.
  Water in the zone of saturation; water
  below the water table[10]. See also
  bathyphreatic, bathyphreatic zone, ground
  water, phreas.

 phreas, dynamic. A phreatic zone or part
   of a phreatic zone where water moves fast
   with turbulence under hydrostatic
   pressure1251.

 phreatic cave.  1. Cave conceived and
   developed by dissolution, usually below
   the water table, where all voids are  water
   filled within the phreas. Phreatic caves
   may include loops deep below the water
   table, particularly in dipping limestone
   with widely spaced bedding-related
   fissures. Higher fissure densities, sub-
   horizontal geological guidance, or greater
   karstic maturity encourage shallow
   phreatic development just below the
   water table. Progressive abondonment of
   phreatic caves is usually in a downward
    sequence, as erosionally lowered valley
    floors intersect lower levels of the flooded
    system. Active phreatic cave segments,
    left perched for geological reasons  after a
    general water-table lowering, are
    relatively common. Characteristics of
    phreatic caves are blind dissolution
    pockets on walls and  ceilings, branching
    and looping of passages, and overall
    switchback gradients as phreatic flow
                                             139

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   may be uphill under pressure.  The most
   common passage, and overall switchback
   gradients as phreatic flow may be uphill
   underpressure.  The most common
   passage form is  a tube, though cross-
   sectional shape reflects local geological
   factors.  A classic active phreatic cave is
   that behind the Fontaine de Vaucluse in
   France, while Holloch, Switzerland, is a
   major system consisting mostly of relict
   phreatic passages191.  2. Cave passage
   developed in the phreatic zone and still
   actively forming. Passages often appear
   as tubes.

phreatic decline.  The downward
   movement of the water tablefI6].

phreatic fluctuation. The fluctuation of the
   water table[16].

phreatic lift. An active or abandoned
   phreatic conduit that carries or carried
   water upwards in a downstream
   directiont9].

phreatic line. See seepage line.

phreatic rise. The upward movement of the
   water tabletl6].

phreatic surface.  See water table.

phreatic water. That part of the
   underground water in a karst limestone
   which lies within the zone of permanently
   saturated rock — the phreatic zone.
   Caves formed within this zone are known
   as phreatic caves[l9\

phreatic zone.  1. Those parts of the earth's
   crust in which all voids are filled with
   water under pressure greater than
   atmospheric[22].  2. That part of the earth's
   crust beneath the regional water table in
   which all voids, large and small, are
   ideally filled with water under pressure
   greater than atmospheric[22].  When
   discussing a karst setting, it is preferable
   to use the term, phreatic zone, so as to
   avoid confusion regarding chemical
   saturation. Synonym: saturated zone.
   See also zone of saturation,  j

phreatobia.  An animal association found in
   water separating grains of sand or fine
   gravel[25].

phreatobite. An inhabitant of groundwater,
   often exhibiting troglomorphy, but not
   limited to karst systems.  Many examples
   of amphipods and other crustaceans
   abound[23].                 j

phreatophyte. Desert plants with deeply
   penetrating roots reaching the water table
   mainly along stream courses[16].
                             i
physiography. The science of the origin
   and evolution of land forms[I6].
                             i
                             i
phytometer.  A device used to measure the
   transpiration of plants embedded in
   soil™.

piedmont plain. A plain extending
   outwards from the base of a mountain
   system[16].                  i

piezometer.  A devise used to measure
   ground-water pressure head at a point in
   the subsurface[22].           \

piezometric head. The sum of me pressure
   and elevation head[16].       !
                                            140

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piezometdc limit. The point within a given
   flow path below which the flow direction
   is influenced by hydrostatic pressure, hi
   cases where flow is confined to a planar
   structure, the piezometric limit can be
   identified as a point where the flow path
   changes from a dip-oriented to a strike-
   oriented trend. The piezometric  limit is
   determined both by discharge rate and
   geometry of the openings. Used to
   describe karst aquifers with a
   discontinuous piezometric surface[14].

piezometric surface. 1. The imaginary sur-
   face to which water from a given aquifer
   will rise under its full static head[10].  2.
   Defined by the elevation to which water
   will rise in artesian wells or wells
   penetrating confined aquifers[16]. See also
   potentiometric surface.

 pigment. A chemical substance that imparts
   color to an object by reflecting or
   transmitting only certain light rays and
   absorbing all others. For example, a
   substance that absorbs all but green rays
   appears green. An object that contains no
   pigment, on the other hand, appears white
   because it reflects all light rays and
   absorbs none. Many troglobites have lost
   all their pigment[23].

 pillar.  1. Remnant of bedrock joining the
   cave floor and ceiling. Not to be
   confused with a column, which is a
   calcite deposit. Pillars are common in
   phreatic caves, formed by complexly
    looping ground-water flow, but may also
   be left as small oxbow cores  of vadose
    origin. A spectacular group of pillars
    occurs in the ill-named Chamber of
    Columns in the Sof Omar cave,
    Ethiopia191.  2. A column of rock
  remaining after solution of the
  surrounding rock. 3. A stalactite--
  stalagmite that reaches from roof to floor
  in a cave; more properly termed a
  column.  4. A tall thin stalagmite that
  does not reach the roof of a cave[10].  See
  column;  rock pillar.

pinnacle karst. 1. Tropical karst
  characterized by vertical rock blades
  fretted sharped by dissolution. It is
  practically indistinguishable from arete
  karst and tsingi, and includes the varieties
  known as shilin.  The Pinnacles in the
  Mulu karst of Saraway have rock blades
  up to 50m high projecting through the
  rain forest canopy191. 2. A tropical
  landscape of bare reticulated saw-topped
  ridges having almost vertical slopes and a
  relief of as much as 120 meters. The
  ridges rise above forest-covered
   depressions and corridors. Found in New
   Guinea at elevations or around 2,000
   meters[20].  Synonyms: (French.) karst a
  pinacles; (German.) Pinnacle Karst;
   (Greek.) karst koriphon; (Italian.)
   carsismo a pinnacoli; (Turkish.)
   sivritepeli karst. Compare cone, cupola,
   tower karst.

 pinnacles. These are a particularly mature
   form of karren. The side walls are grikes
   with Rinnenkarren cutting across one
   another to form sharp edges and peaks
   that can reach several meters in height.
   Generally, pinnacles need a long period
   time to  form. They are common in the
   tropics  and can attain great sizes[3]. Often,
   they are covered. See also debris karren.

 pipe. 1. A generally small, sub-cylindrical,
   vertical hole developed in an
   unconsolidated sedimentary deposit by
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   the washing away of all or part of its fines
   content. Some pipes develop above
   points on a carbonate-rock surface, such
   as joint intersections, where ground-water
   seepage is locally concentrated. Pipes in
   chalk include cylindrical and conical
   masses of clay and sand that are
   neptunian fills of dissolutional dolines,
   shafts and caves; all shapes and sizes are
   commonly referred to as chalk pipes[9]. 2.
   Small cylindrical hole in unconsolidated
   sediments, caused by removal of fine
   material by water[10]. 3. A closed tubular
   conduit for fluid transport^61.

piping. 1. A process whereby a cavity or
   small conduit is developed in an
   unconsolidated soil due to progressive
   sediment removal by seepage water. The
   cavity develops headwards, as the fines
   are removed first and the coarser material
   is then washed out of the growing
   cavity191. Definition 1 is  often incorrectly
   applied to the formation  of sinkhole
   development — the migration of smaller
   particles through openings created by
   larger particles is .of no consequence in
   terms of sinkhole development and
   should not be confused as such.  2.
   Formation of a passage by water under
   pressure in the form of conduits through
   permeable materials when the hydraulic
   head exceeds a certain critical value110]. 3.
   The mechanical washout of caves in
   gravels, soils, loess, etc., and shows
   evidence of associated collapse.

pisanite. A cave mineral —
   (Fe,Cu)SO4-7H2O[11].

pisolite, pisolith. See cave pearl.
pit.  A deep hole, generally circular in
   outline, having vertical or nearly vertical
   wallstl0].  See also jarna; pothole
   (definition 2); shaft.

pitch. Vertical or sub-vertical shaft or cave
   waterfall that normally requires rope,
   ladder or equipment to pass; a term used
   by British cave explorers'91.   ;

piton. 1. (French.) Limestone hill having
   sharply pointed peak[IO].  2. A solid or
   folded metal spike, of steel or i other alloy,
   to be driven into a crack in the rock to
   form an anchort25].

pitot tube.  A device used to measure flow
   velocity via pressure differences116].

pitted plain. Plain having numerous small
   closely spaced closed depressions^101.

plan. A plot of the shape and details of a
   cave projected vertically onto a horizontal
   plane at a reduced scale[25].   [
                              I

planarian.  Aflatworm.  A relatively simple
   wormlike animal with a flattened
   ribbonlike body, a distinct head end, and a
   mouth located more or less centrally on
   the underside of the body[23]. ;

plane of weakness. Surface or narrow zone
   with a shear (or tensile) strength lower
   than that of the surrounding material.
                              I
planimeter. An instrument that
   automatically determines irregular areas
   on a map[I6].                 ;
                              i
plateau. An elevated level land surface116].
                                            142

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Pleistocene. An epoch of the Quaternary
  period, after the Pliocene of the Tertiary
  and before the Holocene; also the
  corresponding worldwide series of rocks.
  It began two million years ago and lasted
  until the start of the Holocene some 8,000
  years ago[1].

plunge pool.  A swirlhole, generally of large
   size, occurring at the foot of a waterfall or
   rapid, on the surface or underground1251.
   See also swirlhole.

pocket.  Solution cavity in ceiling, floor, or
   walls of a cave, shaped like the interior of
   a round-bottomed kettle; unrelated to
   joints or bedding[10].  See also
   spongework.

 pocket valley. 1. The reverse of a blind
   valley, extending headwards into the foot
   of a calcareous massif. The upstream end
   is terminated by a  cliff, frequently lunate,
   from whose base emerges a subterranean
   karst stream meandering across a flat,
   steep-sided valley below the
   resurgence1191.  2. A valley that begins
   abruptly and has no headwaters, having
   formed from and below the site of a
   spring[9].

 pocket storage. Water storage in
    depressions on the land surface1163.

 podzol. A light colored soil, usually found
    in forest regions1161.

 point-bar deposit.  Sedimentation on the
    inside of a meander loop of a river or
    stream channel^61.

  point of inflection.  The point where a
     curve changes slope[16].
point source.  Any discernable, confined, or
  discrete conveyance from which
  pollutants are or may be discharged,
  including, but not limited to, any pipe,
  ditch, channel, tunnel, conduit, well,
  container, rolling stock, concentrated
  animal feeding operation, or vessel or
  other floating craft[22].

poise. A measure of viscosity.

pokrytyi karst.  (Russian.) See covered
   karst.

polarization. The migration and separation
   of ions to the electrodes in a direct current
   electrolyte process giving rise to higher
   overall resistance1161.

polje.  (Slavic word for field.) 1. A large,
   flat floored depression in karst limestone,
   whose long axis is developed parallel to
   major structural trends and can reach tens
   of kilometers in length. Superficial
   deposits tend to accumulate on the floor.
   Drainage may be by either surface
   watercourses (when the polje is said to be
   open) or swallow holes (a 'closed' polje.)
   Their development is encouraged by any
   impedance in the karst drainage1191.  2.
   Polje or karst polje signifies the flat-
   bottomed lands of closed basins which
   may extend over large areas, as much as
    1,000km2. The flat floor of the polje may
    consist of bare limestone, of a nonsoluble
    formation (and so with rolling
    topography),  or of soil. The polje will
    show complex hydrogeological
    characteristics such as exsurgences,
    swallow holes, estavelles, and lost rivers.
    hi colloquial use, the term polje is applied
    to flat-bottomed lands which are
    overgrown or are under cultivation1201.  3.
                                              143

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   Large flat-floored closed karst depression,
   with sharp slope breaks between the
   commonly alluviated floor and the
   marginal limestone.  Streams or springs
   drain into poljes and outflow is
   underground through ponors. Commonly
   the ponors cannot transmit flood flows, so
   many poljes turn into wet-season lakes.
   The form of some poljes is related to the
   geological structure, but others are purely
   the projects of lateral dissolution and
   planation.  The Dinaric Karst has many
   poljes; the Livansko polje is around 60km
   long and 7km wide.  The word is Slovene
   (common also to other Slav languages)
   for a field, reflecting the agricultural
   value of the alluvial polje floor soils[9].
   Synonym: interior valley; (French.) polje;
   (German.) Polje; (Greek.) polye;
   (Italian.) polje; (Russian.) polje;
   (Spanish.) polje; (Turkish.) golova,
  polye; (Yugoslavian.) polje.  See also
   karst polje.

pollutant or contaminant. Includes, but is
   not limited to, any element, substance,
   compound, or mixture including disease
   causing agents, which after release into
   the environment and upon exposure,
   ingestion, inhalation or assimilation into
   any organism, either directly from the
   environment or indirectly by ingesting
   through food chains, will or may
   reasonably be anticipated to cause death,
   disease, behavioral abnormalities, cancer,
   genetic mutation. Physiological
   malfunctions (including malfunctions in
   reproduction or physical deformation in
   such organisms or their offspring1221.

polluted water.  Water that has become
   contaminated by sewage or other
   contaminants such that the water quality
   has become severely degraded.
                             I

pollution.  1. Specific impairment of water
   quality by agricultural, domestic, or
   industrial wastes (including thermal and
   atomic wastes), to a degree that has an
   adverse effect upon any beneficial use of
   water[22].  2. The addition to a stored body
   of water of any material which diminishes
   the optimal economic use of the water
   body by the population which it serves,
   and has an adverse effect on the
   surrounding environment^21. I

pollution abatement. All measures taken
   to prevent or to protect against
   pollution1161.                ;

polygonal karst.  1. A karst area where the
   surface is completely pitted with closed
   depressions, the  divides of which form a
   crudely polygonal network. Especially
   common in humid tropical cone-karst
   terrain, but also found in well-formed
   temperate doline-karst terrain1?0-1. 2. A
   type of karst in which numerous closed
   depressions are separated by dividing
   ridges that impose a crudely pdlygonal
   appearance upon the landscape'91.

pond. A small body of surface water1161.

ponded water.  Water held in a depression
   by a barrier[161, such as breakdown in a
   cave system.

ponor. (Slavic.) 1. Hole or opeijting in the
   bottom or side of a depression where a
   surface stream or lake flows either
   partially or completely underground into
   the karst ground-water system.  A sea-
   ponor is where sea-water  flows or is
                                           144

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  drawn into an opening by a vacuum in
  karstified rock[20]. 2. Hole in the bottom,  ,
  or side of a closed depression through
  which water passes to or from an
  underground channel[10].  Synonyms:
  (British.) swallet, swallow hole, stream
  sink; (French.) ponor, oven, gouffre,
  perte; (German.) Schlund, Saugloch,
  Schlinger, Ponor, (Greek.) katavothra;
  (Italian.) inghittitoio, capovento;
  (Russian.) ponor, (Spanish.) sumidero,
  ponor, perdida; (Turkish.) suyutan;
  (Yugoslavian.) ponor, utok, poziralnik,
  pivka. See also swallow hole.

ponornica. See lost river.

pool deposit. Crystalline material deposited
  in an isolated pool in a cave[10].

population.  Individuals of a species in a
  given locality which potentially form a
  single interbreeding group separated by
  physical barriers from other such
  populations (e.g., populations of the same
  species in two  quite separate caves)[253.

pore. Small void space in rock or
  unconsolidated material of soil particles.
   See also interstice1163.

pore deposit. Mineral matter deposited on
   the interior of a cave from water entering
   the cave so slowly through pores and
   cracks that it does not form drops[10].

pore entry radius. The radius of a flow
   channel at pore entry, usually smaller than
   the average pore radius[16].

pore pressure. The pressure of water in
   pores of a saturated medium[16].
pore space. 1. The total space not occupied
  by splid soil or rock particles1223. 2. The
  space occupied by voids containing gases
  or liquids in soil or rock samples[16].  See
  also interstice; porosity; porosity,
  effective; porosity, primary; porosity,
  secondary.

pore velocity. See velocity, average
  interstitial.

porosimeter. A device used to measure
  porosity[16].

porosity. 1. The ratio of the aggregate
  volume of interstices in a rock or soil to
  its total volume; generally stated as a
  percentage[10]. 2. The ratio, usually
  expressed as a percentage, of the total
  volume of voids of a given porous
  medium to the total volume of the porous
  medium[22]. 3. The volume percentage of
  the total bulk not occupied by solid
  particles[22].  See also porosity, effective;
  porosity, primary; porosity, secondary;
  porosity, tertiary.

porosity, absolute.  Porosity established by
   taking into account all interconnected and
   nonconnected or isolated void volumes'16].

porosity, effective.  1. The ratio, usually
   expressed as  a percentage of the total
   volume of voids available for fluid
   transmission to the total volume of the
   porous medium[22]. 2. The ratio of the
   volume of the voids of a soil or rock mass
   that can be drained by gravity to the total
   volume of the mass[22]. 3. The amount of
   interconnected pore space and fracture
   openings available for the transmission of
   fluids, expressed as the ratio of the
   volume of interconnected pores and
                                             145

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   openings to the volume of rock. See also
   porosity; porosity, primary; porosity,
   secondary; porosity, tertiary.

porosity, primary. Porosity of some
   lithological material that developed while
   the rock was forming. See also interstice;
   pore; pore space; porosity; porosity,
   effective; porosity, secondary.

porosity, secondary. Porosity of some
   lithologic material that has developed
   after the rock was initially formed, such
   as joints and fractures, and maybe
   capable of enlargement by dissolution
   processes. See also pore; pore space;
   porosity, effective; porosity, primary;
   porosity, tertiary.

porosity, tertiary. Porosity caused by
   solutional enlargement of secondary
   porosity. See also pore; pore space;
   porosity; porosity, effective; porosity,
   primary; porosity, secondary.

porous.  Having numerous interstices,
   whether connected or isolated.

porous medium. Any medium containing
   interdispersed void spacetI6].

porthole. A nearly circular natural opening
   in a thin rock wall in a cave[IO]. See also
   window.

potable water. Water that is suitable for
   human consumption[22].

potamology. The study of streams.

potential.  Any of several different scalar
   quantities, each of which involves energy
  as a function of position or of condition;
  e.g., the fluid potential of ground waiter[22].
                              I
potential density. 1. The density of a unit
  of water after it is raised by an adiabatic
  process to the surface, i.e., determined
  from in-situ salinity and potential
  temperature1221. 2. Density that would be
  reached by a compressible fluid if it were
  adiabatically compressed or expanded to a
  standard pressure[22].

potential drop. The difference in total head
  between two equipotential lines[22].

potential evapotranspiration  Evapotran-
  spiration occurring under adequate soil-
  moisture supply at all times for given
  temperature and humidity conditions1161.

potential flow. Irrotational flow occurring
  in a conservative force field or potential
  field^.                    |

potentiometer. An instrument used to
  measure voltage differences1'6].

potentiometric field.  As used ill karst
  hydrology, a discontinuous highly
  irregular surface representing the sta.tic
  ground-water head as indicated by the
  level to which water rises in ajselected
  piezometer, hi some piezometers, the
  water-level rise will be greatly different
  from other piezometers (either higher or
  lower) or may be non-existent all
  together.

potentiometric surface. An imaginary
  surface representing the total static head
  of ground water and defined by the level
  to which water will rise in a  ;
                                            146

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  piezometer[22]. Replaces the term
  piezometric surface.                  ;,

pothole. 1. A single shaft, or an entire cave
  system that is dominantly vertical. It is
  also used to describe a single erosional
  bowl or moulin, rounded mainly by the
  swirling current, in a stream bed[9]. 2. A
  small rounded hole pipe worn into the
  bedrock of a streambed, or on the coast,
  or at a waterfall, by sand, gravel, and
  stones spun around by the current in
  evorsion or mill action[20]. 3. Term used
  in England for vertical or steeply inclined
  shaft in limestone[10].  Synonyms:
  (French.) marmite de geant, aven;
  (German.) Kolk, Strudelloch; (Greek.)
  strongili opi is petrothi latin revmatos;
   (Italian.) marmitta dei giganti;
   (Russian.) karstovaja sahta; (Spanish.)
   marmita de gigante, pilancon; (Turkish.)
   dev kazam; (Yugoslavian.) erozioni
   kotas. See also pit; shaft.

 potholer. (British.) Explorer of openings in
   karst formations with emphasis on
   vertical and steep openings; somewhat of
   a slang term1201. Synonyms: (French.)
   speleologue; (German.) Spelaologe,
   Hohlenforscher; (Greek.) erevna
   karstikon engelon; (Italian.) speleologo;
   (Spanish.) espeleologo, explorador de
   simas; (Turkish.) dev kazancv,
   (Yugoslavian.) speleologjamar.  See
   speleologist, caver.

 potholing.  1. The process of scouring holes
   in rock in stream beds or near the strand
   line by rapid rotation of trapped pebbles
   or cobbles; evorsion[10]. 2.  (British.) See
   caving.

 pozo.  (Spanish.)  See sima.
preadapted. Possessing adaptations that
  would Contribute to survival in a habitat
  other than the immediate one because of
  similarities in living conditions in the two
  habitats.  Insects that live in leaf litter on
  the forest floor, for example, maybe
  pre-adapted to cave life[23].

precipitation.  1. Water precipitating in
  liquid or solid form from the
  atmosphere[16].  2. The growth and
  development of crystals from solutions
  that are supersaturated with respect to
  various minerals.

precipitation excess. That part of
  precipitation that contributes directly to
   runoff1161.                 ;

precipitation gage. An instrument used to
   measure the amount of precipitation per
   unit area[16].

predator. An  animal that lives by capturing
   other animals for food[23].  See also prey.

 pressure. The force exerted across a real or
   imaginary surface divided by the area of
   that surface.

 pressure cell.  A pressure measuring and
   transducing device[16].

 pressure cell.  The pressure difference
   occurring between two points along a
   stream line  in a flow system^61.

 pressure flow tube. Gallery with water
   flowing under pressure including
   differential  gravity head and artesian
   pressure1201.  Synonyms: (French.) galerie
   en conduite forcee; (German.)
   Druckstromungsrohre, Karstgerinne;
                                             147

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   (Greek.) ypoghion ytnatagogos,
   ypopiesin; (Italian.) condottaforzata;
   (Russian.) karstovij kanal s napornimi
   vodami', (Spanish.) galena (o tubo)
   saturada; (Turkish.) basinch su mecrasi;
   (Yugoslavian.) kanal s vodom pod
   tlakom.  See also conduit; streamtube.

pressure head. Hydrostatic pressure
   expressed as the height of a column of
   water that the pressure can support at the
   point of measurement^21.  See also head,
   static; pressure, hydrostatic.

pressure, hydrostatic. The pressure
   exerted by the weight of water at any
   given point in a body of water at rest1221.

prey. A living animal that is captured for
   food by another animal[231. See also
   predator.

prism storage. The storage of water in a
   river channel or reservoir in prism above
   the original water level[16].

prismatic compass. A compass with a
   prism attached so that the compass card
   can be read at the same time as  the
   compass is directed into the line of sight
   to a distance point[25].

probe.  A sensing instrument used to take
   measurements at the interior of a
   relatively unaccessible system[16].

producers.  Green plants, the basic link in
   any food chain; by means of
   photosynthesis, green plants manufacture
   the food on which all other living things
   ultimately depend.  They are available in
   the cave community only in the twilight
   zone, or as debris that falls or washes in.
   A few types of bacteria also manufacture
   food from nonliving substances and
   therefore serve as producers in some cave
   communities1231.  See also consumer.

projected section.  The result of projecting
   a section composed of several parts with
   differing directions onto a single plane.
   Usually the plane is vertical along the
   general trend of the cave.  The horizontal
   distance apart of points is not correct,
   only the vertical, so that sloped are
   distorted1251.                 <

proto-cave. Natural void that links a
   potential input point and an output point
   within an aquifer, but which is still too
   small to be entered by man[91.!

prusik knot. A knot tied by looping a
   smaller diameter rope around a larger
   standing line (rope) that has tlie property
   of sliding with no load on the knot, but
   will hold when it is loaded (e.g. when the
   weight of a caver is applied)1131. See also
   ascender; mechanical ascender; prusiking;
   standing line.                [

prusik sling. A sling fastened by a prusik
   knot to the rope[25].           |
                              |
prusiking.  The art of ascending! a standing
   line (rope) by a caver with prusik kn.ots[13]
   as opposed to the use of a mechanical
   ascender. See also ascender; knots;
   mechanical ascender; prusik knot;
   standing line.                ;
                              |
pseudokarren. These are karreri appearing
   features that form mostly on insoluble,
   silicate rocks by means of weathering
   processes. They appear as a rounded type
   of Rinnenkarren and less frequently as an
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  atypical form of solution pan[3].  See also
  karren; Rinnenkarren; solution pan.   ;.

pseudokarst.  1. Terrane with features
  similar to karst but formed in nonsoluble
  rocks, as by melting of permafrost or
  ground ice, collapse after mining, and by
  outflow of liquid lava from beneath its
  solidified crust[20].  2. Karst-like terrane
  produced by a process other than the
  dissolving of rock, such as the rough
  surface above a lava field, where the
  ceilings of lava tubes have collapsed.
  Features of pseudokarst include lava
  tunnels, lava tubes, lava stalactites, and
  lava stalagmites[10]. 3. A landscape
  containing karst-like features such as
  caves and dolines, but not formed by
  bedrock dissolution as in true karst.
  Pseudokarst embraces volcanic
   landscapes with lava caves, cryokarst or
   thermokarst formed by ground-ice
  melting in a permafrost environment, and
   situations where mechanical soil piping
   has occurred, producing depressions and
   pipes, as occur commonly in areas of
   loess cover[91. Synonyms: (French.)
  pseudokarst; (German.) Pseudokarst;
   (Greek.) psevthokarst; (Italian.)
  pseudocarsismo; (Russian.) psevdokarst;
   (Spanish.) pseudokarst; (Turkish.)
   aldatici karst; (Yugoslavian.) pseudoks
   pseudokras, pseudokarst, navidezni kras.
   See lava cave, lava karst, pahoehoe.

 pseudo-breccia. A type of limestone
   resembling a breccia, in which angular
   limestone fragments are cemented
   together by limestones of different
   composition. Pseudo-breccias are
   common in many preserved limestone
   sequences and may owe their origin to the
   dissolutional removal of originally
   interbedded and interstitial sulfate
  minerals followed by break-up and
  redistribution of the residual carbonate
  component191.

psychrometer. 1. An instrument used for
  measuring relative humidity.  The
  simplest sling psychrometers; consist of
  two thermometers mounted on a rotating
  frame. One thermometer's bulb is kept
  moist, the other dry.  By comparing the
  "wet bulb" and "dry bulb" readings of the
  two thermometers after they have been
  whirled in the air, one can determine the
  relative humidity. An electric fan is used
  to ventilate the wet bulb in many
  psychrometers[23]. 2. Apparatus designed
  to measure relative humidity indirectly1'61.
  See also hygrometer.

puddle.  Water collecting in very small
   surface depressions^61.

pumping test.  A test designed to determine
   aquifer characteristics by pumping a well
   and plotting the drawdown curves of
   observation wells for comparison with
   theoretical curves.

pupa (plural pupae). The inactive stage in
   the life history of certain insects during
   which the larva undergoes aigradual
   reorganization of its tissues in the process
   of becoming an adult.  See also
   metamorphosis.

 pycnometer.  A bottle with an accurately
   determined volume for density
   determinations^63.

 pyrite. Iron sulfide mineral (FeS2) also
   known as iron pyrites and fool's gold.
   Pyrite occurs in trace amounts in many
   sedimentary rocks. It may be locally
                                             149

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  common in dark carbonaceous limestone
  and in thin non-carbonate beds such as
  shales, coals and wayboards.  Pyrite may
  break down spontaneously, with or
  without bacterial mediation, to form
  sulfates, particularly sulphuric acid, that
  maybe involved in early speleogensis[9].

pyrrhotite.  A cave mineral — FeS[11].
                                            150

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                    Q
quagmire. A wet unstable land area[16].

quartz. A crystal form of silicon dioxide
   (Si02)[16]. '

quiet reach. The reach of a river with no
   features disturbing the flow pattern[16].
                                              151

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                    R
rabies.  An infectious disease of the central
  nervous system in mammals, caused by a
  lyssavirus. Usually transferred by the bite
  of an infected animal, such as dogs,
  skunks, racoons, or rarely bats.
  Characterized by choking, convulsions,
  inability to swallow, etc. Different
  genetic strains are now recognized and
  can be identified by tests. Transfer of
  rabies from bats via aerosols to caged
  animals in a cave has been demonstrated,
  but has not been proven in humans[23].

radial flow.  1. Radial flow into or out of a
  well under ideal circular boundary
  conditions1161.  2. The flow of ground
  water in all directions in response to
  recharge entering the subsurface at or
  near the top of a ground-water plateau.
  This  conditions occurs most often
  through point recharge entering the
  subsurface via sinkholes in karst terranes.

radioactive tracer.  A tracer used in
  hydrological direction and velocity
  determinations1161.  The two most
  common types are tritium and deuterium.

radioactivity log. A log measuring
  radioactivity in a borehole[161.

radioisotope. An unstable isotope of an
   element that decays or disintegrates
   spontaneously, emitting radiation'221.

radionuclide. A radioisotope[22].

radionuclide retardation.  The process or
   processes that cause the time required for
   a given-radionuclide to move between
   two locations to be greater than the
  ground-water travel time, because of
  physical and chemical interactions
  between the radionuclide and the
  geohydrologic unit through which the
  radionuclide travels[22].       i

radius of influence. The radial distance
  from the center of a well bore |to the point
  where there is no lowering of the water
  table or potentiometric surface (the edge
  of its cone of depression)'61.
                              i
raft. A thin sheet of crystalline calcite
  supported by surface tension on a ca.ve
  pool or lake. The calcite is precipitated
  mainly in response to evaporation of the
  pool water and rafts are therefore found
  mainly in caves in arid regions or catves
  with powerful through draughts.

rain. Liquid precipitation of atmospheric
  water  in the form of droplets[16].

rainfall excess. That portion of :rain fall that
  contributes directly to runoff11;61.

rainfall intensity. The volume or depth of
  rainfall per unit time'161.

rain gage. An instrument used to measure
  the height of rainfall1161.      j
                              E
rain gage network. An areal distribution of
  rain gages[16].               i

rain intensity. The intensity of rain fall
   expressed in depth per time (in/hr)[16].
                              i
randpolje.  An enclosed plain at the edge of
   a karst area receiving surface Water from
   the  nonkarstic area. The water drains out
   through underground passages in the karst
   area.  The plain is thus completely
                                             152

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  enclosed by higher ground. Compare £f:
  blind valley; karst margin plain[10].

rappel. The art of descending a rope using
  some sort of friction between the rope and
  the rappeller to control the rate of
  descent^31. Synonym: abseil. See also
  abseil; carabiner.

rappel rack. A long U-shaped steel bar that
  holds several brake bars and is used for
  rappelling1131.  See also rappel.

rappel spool.  One of the devices used to
  create friction between a rappeller and the
  rope that consists of a spool on which the
  rope can be wrapped around several
  times[13].  See also rappel.

rapid. A stream section with a notably
  higher flow velocity than in adjoining
  partsf161.

rapid flow. Open channel flow with a
  Froude number greater than unity[I6]. See
  also Froude Number.

rate of draft.  The rate at which water is
  required for use (demand)'161.

rate of infiltration.  The maximum rate at
  which soil can absorb water[16].

rating curve.  The graphic relationship of
   stage to discharge1161.

rational formula. An equation relating
   runoff intensity and area to a runoff
   coefficient^61.

ravine. A small erosional depression[16].
   See chasm.
raw sewage.  Untreated sewage.

raw water. Untreated water[16].

reaction path modeling. A simulation
  approach to studying the chemical
  evolution of a (natural) system1221.

rebelay. The reanchoring of a rope, usually
  to avoid rub points or split long pitches.

REDIRECTION Syn. deviation

rebound. An upward movement of soil as a
  consequence of a decrease in effective
  stress. In fine-grained soils, rebound is
  usually much less than the amount of
  compaction since compaction is mostly
  irreversible^11.

receiver.  That part of a remote measuring
  system that receives  incoming data or
  impulses1161.

receiving surface. A surface receiving
  precipitation or radiation1'6].

recessional moraine.  A moraine deposited
  by a retreating glacier[16].

recession curve. The falling limb of a
  hydrograph curve[16].

recession flow.  The flow that occurs after
   rainfall has ended[16].

recession segment. That part of a
   hydrograph that represents the withdrawal
   of water from storage[16].

recharge.  1. The process of addition of
   water to the saturated zone[22].  2. The
   artificial replenishment of a depleted
                                            153

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   aquifer by injection or infiltration of
   water from the surface[16].

recharge, allogenic. Recharge derived from
   runoff of neighboring or overlying non-
   karst rocks that drains into a karst aquifer.
   Diffuse allogenic recharge is used to
   describe the slow percolation of recharge
   when runoff into direct input points is
   reduced in magnitude while concentrated
   allogenic recharge is used to describe the
   concentrated recharge that occurs by
   runoff into large fractures, sinkholes, and
   sinking streams.

recharge area. An area in which water
   reaches the zone of saturation by surface
   infiltration^221.  See also intake area.

recharge, autogenic. Recharge derived
   from precipitation directly onto the karst
   landscape. Diffuse autogenic recharge is
   used to describe the slow percolation of
   recharge through a myriad of small
   openings while concentrated autogenic
   recharge is used to describe the
   concentrated recharge that occurs by flow
   into large fractures, sinkholes, and
   sinking streams.-

recharge capacity. The ability of the soils
   and underlying materials to allow
   precipitation and runoff to infiltrate and
   reach the phreatic zonep2].

recharge line.  A series of recharge wells
   arranged in linear fashion to approximate
   a line source[16].

recharge pit.  A large diameter well or shaft
   for recharge under gravity1'61.
recharge water. Water used for;
  replenishment of a depleted aquifer[16].
                              l
recharge well, absorbing well, diffusion
  well, inverted well. A well that is used
  to recharge water back into anlaquifer.
  Commonly used when aquifer.depletion,
  saltwater intrusion, and contaminant
  migration are problems.

recipient. A vessel receiving liquids in
  volume measurements'161.    ,

reclamation. To reclaim land after abusive
  effects such as strip mining.

recorder. An instrument designed to
  continuously or intermittently record
  measurements'161.            j

recovery. The water-level rise in a well
  occurring upon the cessation of discharge
  from that well or an observation well.

recovery method. A pumping test analysis
  method in which both drawdown and
  recovery of head after cessation of
  pumping are observed and plotted  for the
  same observation well[I6].

recrystallization.  A new formation of
  crystals from solid rock material116].

reculee. See pocket valley.

redirection.  See deviation.    ;

redox.  A chemical reaction in which an
   atom or molecule loses electrons to
   another atom or molecule. Also known as
   oxidation-reduction. Oxidation is  the loss
   of electrons; reduction is the gain of
   electrons161.                 ,
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redox potential (Eh.) Oxidation-reduction
  potential[16].

reef. A dissected ridge of rocks totally or
  partially submerged in sea water; often of
  organic origin[16].

regelation.  The melting of ice under
  pressure and subsequent freezing[16].

rigging. The process of establishing the
  belays for SRT or laddering1251. See also
   single rope technique.

region of dispersed water. The diffuse
   interface between freshwater and sea
   water caused by mixing in a coastal
   aquifer[16]. See also transition zone.

regolith. A general term for the layer of
   fragmental and unconsolidated rock
   material that nearly everywhere forms the
   surface of the land and overlies or covers
   the bedrock[6].

regosol. Dry sandy soil[16].

regression line.  A curve fitted to all mean
   values of one variable[16].

rejuvenation.  A process that interrupts an
   active erosional or development cycle and
   initiates a new cycle.  Rejuvenation is
   most commonly achieved  in the karst and
   speleogenesis context by erosional base-
   level changes caused by relative uplift (or
   sea-level fall) or by local water-table
   changes caused by downcutting of surface
   valleys intercepting deeper drainage
   lines[9].

 relapsing fever. One type ofBorreliosis,
   caused by various species ofBorrelia
  spirochaetes carried by several species of
  tick. Related to Lyme disease, but less
  chronic and milder. An occupational
  disease of some cavers in Texas who
  come in contact with the soft tick
  Ornithodoros turicatae, which carries
  Borrelia turicatae and may live in cave
  entrances[23].

relative humidity of atmosphere. The
  ratio of absolute humidity to the
  maximum possible saturation at given
  conditions1161.

relative permeability. See permeability,
  relative.

relict cave. Abandoned, inactive cave
  segment, left when the water that formed
  it is diverted elsewhere, normally due to
  rejuvenation, continuing cave
  development and increasing karstic
  maturity. Relict unmodified phreatic
  passage segments are abandoned in the
  vadose zone, where they may remain dry,
  retaining a typical phreatic morphology,
   or be invaded and modified to a keyhole
  profile by new streams. Ages of relict
   caves vary greatly and due to lack of
   stream-flow breakdown and speleothem
   deposition may become the dominant
   processes. Relict caves are commonly
   referred to incorrectly as fossil caves[9].

 relict karst. A karst area that exists within
   the contemporary system, but has been
   removed from the situation in which they
   developed, usually as a result of base-
   level changes.

 relief.  Elevation differences in topography
   of a land surface[16].
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relief intensity.  The average altitude
   difference between the highest point of a
   basin and the valley bottom1161.

replenishment.  The restoration of water in
   a depleted aquifer1161.

resequent river. A river flowing according
   to a consequent drainage pattern but at a
   lower level than the original slope[161.

reservoir.  1. A recipient for the collection
   of small amounts of liquid[16].  2. A
   surface water impoundment^161.

reservoir evaporation.  Evaporation from
   the free surface of impounded water
   bodies1161.

reservoir lake. A lake obtained by the
   impoundment of water for storage
   purposes1161.

residual clay.  Clay or sandy clay remaining
   on a rock surface after removal of
   calcium carbonate by solution. Compare
   terra rossa1101.

residual drawdown. The rise in water level
   in a well in response to cessation of
   pumping.

residual hill. See emergence.

residue. Solids remaining after
   evaporation1161.

resurgence. 1. Re-emergence of karst
   ground water a part or all of whose waters
   are derived from surface inflow into
   ponors at higher levels^201. Point at which
   an underground stream reaches the
   surface and becomes a surface stream. In
  European literature, the term is reserved
  for the re-emergence of a stream that has
  earlier sunk upstream; the term
  exsurgence is applied to a stream without
  known surface headwaters[10].; Synonyms:
  (French.) resurgence; (German.)
  Karstquelle; (Greek.) kephalari;
  (Italian.) risorgenza; (Russian;) vihod
  karstovih vod; (Spanish.) resurgencia;
  (Turkish.) sugikan; (Yugoslavian.) kf&i
  izvor (vrelo), obrh. See emergence.
  Compare exsurgence.

retardation factor. The ratio of the average
  linear velocity of ground water to the
  velocity of the retarded constituent at
  C/C0=0.5[22].

retention.  1. The detention of water on
  surface depressions or in subsurface void
  space. 2. the retention of water in pores
  against gravity1161.            i

reverse fault.  A fault where relative
  movement of the hanging wall has
  occurred in the upward direction^161.

Reynolds number. A numerical quantity
  used as an index to characterize the type
  of flow in a hydraulic structure in which
  resistance to motion depends on the
  viscosity of the liquid in conjunction with
  the resisting force  of inertia. It is the ratio
  of inertia forces  to viscous forces, and is
  equal to the product of a characteristic
  velocity of the system (e.g. the mean,
  surface, or maximum velocity) and a
  characteristic linear dimension, such as
  diameter or depth, divided by the
  kinematic viscosity of the liquid; all
  expressed in consistent units in order that
  the combinations will be dimensionless.
  The number is chiefly applicable to
  closed systems of flow, such as pipes or
                                            156

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  conduits where there is a free water
  surface, or to bodies fully immersed ili the
  fluid so the free surface need not be
  considered[1].  See also Chezy equation;
  Froude number; Manning equation.

rhodamine dye, sulpho rhodamine dye.
  Orange dyes used in environmental
  tracing studies that fluoresce red when
  held under a black light. See also
  fluorescent dyes.

rice paddy, hi a cave, a terraced rimstone
  pool^.

ridge.  An elongated narrow elevation1161.

rift. 1. A cave passage that is relatively high
  and narrow. Generally rifts are straight or
  nearly so, reflecting that they are
  commonly guided by, and developed
  along, vertical or sub-vertical fissures, '
  joints and faults191.  2. A long narrow high
  cave passage controlled by joints or
  faultstIO].

rift valley. A surface depression due to the
  formation of graben block faulting[16].

rill. 1. Small solution groove on surface ex-
  posures of limestone; most common in
  arid or semiarid areas1101. 2. Small
  channel cut by flowing water in the floor,
  wall, or ceiling of a cave[20]. 3. The
  smallest category of stream in any
  terrane[201. Synonyms: (French.) traces de
  ruissellement; (German.) Rinne, Kerbe;
   (Greek.) ridkion; (Italian.) solchi di
   ruscellamento; (Spanish.) arroyuelo;
   (Turkish.) ku$uk dere, oluk, ark.

Rillenkarren. (German.) Solution flutes
   that occur only in places where fresh
  unspent precipitation is active and end
  whe'fe the water attains too high a content
  of lime or where water is added.  Their
  length increases with slope, temperature,
  and rainfall; eventually reaching 1 m and
  more in the tropics, up to 50 cm, and as
  an exception, 100 cm in the Alps. Their
  width extends from 1 to 3 cm.  They lie
  together in rows with no space between,
  with sharp intermediary ridges of no more
  than 1 cm in height.  They increase at all
  freely exposed peaks and ridges where
  fresh rainwater alone is at work.  The
  grooves gradually flatten out to a smooth
  surface. Their theory of origin is
  unknown.[3]. Synonyms: (German.)
  Kannelierungen; solution flutes; and
  firstkarren.

Rillenstein.  (German.) Microsolution
  grooves and pitting on rock surface1101.

rimstone. 1. A wall-shaped deposit around
  springs and below cascades which
  impounds water in pools. Its formation is
  due to precipitation from saturated
  bicarbonate waters1201.  2. Calcareous
  deposits formed around the rims of
  overflowing basins, especially in caves[10].
  Synonyms:  (French.) gour; (German.)
  Sinterbecken; (Greek.) frdgma,
  epiphliomatos; (Italian.) vasche
  d'incrostazione; (Russian.) natecnaja
  plotina; (Spanish.) dique travertinico;
  (Turkish.) sedde, kenarta^i.  See
  constructive waterfall, rimstone barrage,
  rimstone pool.

rimstone barrage, rimstone barrier, rim-
  stone dam. A wall-shaped deposit that
  impounds pools of water in caves,  around
  springs, and in cascades of streams
  saturated with calcium bicarbonate1101.
                                            157

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  Synonym: (French.) gour. See also
  rimstone; rimstone pool.

rimstone pool. A pool sited on a cavern
  floor and enclosed by a rim of carbonate
  reprecipitated from the karst water in the
  pool at points locally favoring the release
  of carbon dioxide[19].  See also rimstone;
  rimstone barrage.

Rinnenkarren.  (German.) Solution grooves
  that form where runoff water is collected
  in streams.  If the whole surface is
  moistened, the amount of water increases
  downwards with the result that the
  grooves are widened and deepened at the
  bottom. This distinguishes them from
  other similar forms. When the slope is
  slight they are coiled, but become
  straighter with increasing inclination.
  They are sometimes interpreted to be
  subcutaneous forms that develop below
  soil cover, but this is believed to be a rare
  occurrence. They are found in all
  climates. In arid zones, they exist as
  relics of the past when the climate was
  damper131.

ripple mark.  A w-avelike sculpture on
  water covered sand surfaces obtained by
   wave action1161.

rise. (Jamaican.) Spring rising from
   fractures in limestone. Point at which an
   underground  stream comes to the
   surface1101.

rise pit. An artesian spring rising up
   through alluvium accumulated in an
   earlier surface valley phase and often
   fringed, except on the outlet side, by a
   minor levee deposited as the force of the
  vertical discharge dissipates at! the
  surface[191.

riser. A pipe through which liquid rises in a
  well1161.                     ;

riser pipe. A pipe through which water is
  raised in a production well[16].:
                              i
rising.  1. The resurgence of an underground
  watercourse, usually at the base margin of
  the calcareous massif,  although in the
  instance of a blind valley the rising has
  eroded headwards for some distance.
  Each rising accounts for the collective
  discharge of several sinks andiin this way
  has a relatively high discharge as the sole
  drainage outlet for a large area.  If the
  water issues freely, the rising is said to be
  free-flowing, but if it issues under
  pressure, the terms artesian, forced, or
  vauclusian spring are used (after the type-
  example of the resurgence of the Sorgue
  river at Vaucluse in France)[19].  2. An
  issue of water from massive limestone
  which cannot be classed with pertainty as
  either a resurgence or  a spring[20].
  Synonyms: (French.) emergence;
  (German.) Ausflufltelle, Karsiquelle;
  (Greek.) kephalari; (Italian.) sorgente;
   (Russian.) vihod karstovih vod;
   (Spanish.) emergencia', (Turkish.)
  yuzeye yilkseli§; (Yugoslavian.) krsko
   vrelo, krski izvor, obrh. See also
   emergence; exsurgence; resurgence.
                              i

 rising segment. That part of a hydrograph
   curve that represents a rise in water level
   as a result of precipitation1161.;

 river. A natural water course through which
   runoff reaches the sea[I6].    ',
                                             158

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river bed. The channel of a river covered
  bywater[161.

river reach. A particular segment of a
  river[16].

river swamp.  A swamp in lowlands
  adjoining a river[16).

river system.  The system of a main river
  that includes all its branches and
  tributaries[16].

river terrace. A level land terrace formed
  in a valley by fluviatile erosion or
  aggradation^161.

rivulet. A very small stream1161.

rock.  Consolidated mineral matter of
   igneous, sedimentary, or metamorphic
   origin[16].

rock fall. See cave breakdown.

rock formation.  A lithologically or
   structurally distinct part of the
   lithosphere[16].

rock-hill. See karren, rill.

rock milk.  Less common synonym for
   moonmilk[9]. See moonmilk.

rock pendant. See pendant.

 rock pillar. A residual isolated mass of
   bedrock linking the roof or overhanging
   wall and floor of a cave, in contrast with a
   column, which to composed of dripstone
   or flowstone[10]. See column; pillar.
rock pinnacle.  A tall sharp projection of
  bedrock rising from the floor of a cave[10].

rock shelter. 1. Shallow cave under an
  overhanging rock ledge. Many sea caves
  are rock shelters. Also found in limestone
  and other rock types where streams have
  undercut their banks at bends, or where
  there has been abrasion by blowing sand.
  Common in tropical areas at places where
  a secondarily hardened layer of limestone
  forms a ledge that projects over
  unindurated limestone[10].  2.. A wide but
  shallow cavity in any rock; in carbonate
  rock often formed below a noncarbonate
  layer[20]. Synonyms: (French.) abri sous
  roche, balme, baume; (German.)
  Halbhohle, weite aberflache Hohle;
  (Greek.) kataphyion; (Italian.) riparo
  sotto roccia, androne; (Spanish.) abrigo,
  balma; (Turkish.) kaya sigiriagi;
   (Yugoslavian.) potkapina, okapina,
  polupecina, spodmol, zijalka.

 rock system. Rocks deposited during a
   given geological time period[16].

 rock terrace.  A terrace formed by erosional
   action and denudation[16].

 rock texture.  The geometrical aspects and
   arrangement of the component particles of
   arock[16].

 rockhole. A shallow, small hole in rock
   outcrops, often rounded in form and
   holding water after rains. Well known on
   the Nullarbor Plain, Australia1251.

 rockpile. A heap of blocks in a cave,
   roughly conical or part-conical in
   shape[25!.
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rockfall. The falling of bedrock from a cliff
  or steep slope1161.

romanechite. A cave mineral —
  BaMn9016(OH)4[11].

roof crust. Flowstone deposited on ceilings
  of caves from thin films of water, which
  have crept over the rock from pore or
  crack sources^101.

roof drainage.  Precipitation runoff from
  roofs.

roof pocket. Blind upward extension into
  the ceiling of a cave passage, commonly  .
  enlarged by dissolution along a transverse
  fracture, and less extensive than an aven
  or chimney191.

roof slab. See ceiling slab.

room. A part of a cave system that is wider
  than a passage1101.  Synonym: (British.)
   chamber.

root karren. These are small, relatively flat
  karren that are formed beneath compact
   soils where roots etch into the
   limestone133.  See also covered karren;
   wave karren.

root zone. The zone in a soil profile
   penetrated by plant roots[I6].

rope protector. A length of heavy fabric or
   plastic hose placed around a rope where it
   may rub against rock[25].

rotating meter. A stream velocity meter
   that transforms stream momentum into
   angular momentum by vanes and rotor[16].
roughness. An unevenness of surfaces
  giving rise to high flow resistances1'61.

roughness coefficient.  A coefficient that
  describes roughness of a chanriel bed[16].
                              I
round karren.  See Rundkarren.j

roundness.  The degree to which a sand
  grain approaches spherical shape1161.

rout, to. The action of predicting and
  directing of flood waves through a
  channel system[16].

run dry, to. The cessation of flow from a
  well or spring[16].            I

Rundkarren.  (German.) 1. Karien forms
  with rounded edges; formed by soil water
  than cannot flow freely due to the
  tightness of soil pores and thus corrodes
   away all edges and points. The  small
  karren forms disappear, grooves and
   grikes are widened and deepened. One or
   two centuries after being laid bare, the
   earlier rounded edge is only just
   recognizable so round karren and their
   remains provide evidence of an earlier
   soil covering[3].  2. Karren form
   comprising rounded channels^ commonly
   50-500mm deep and wide and separated
   by rounded ridges. Rundkarreji  are the
   characteristic dissolutional form created
   beneath superficial material such as sandy
   till, peat or other soil, or beneath a cover
   of plants or lichen[9]. Synonym: round
   karren. See also Karren.

 runoff.  1. The discharge of water through
   the surface streams of a drainage basin[!6].
   2. The sum of surface runoff and ground-
   water flow that reaches a stream116].
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runoff coefficient. A dimensionless
  coefficient to estimate runoff as a certain
  percentage of storm rainfall[16].

rupture. That stage in the development of a
  fracture where instability occurs. It is not
  recommended that the term rupture be
  used in rock mechanics as a synonym for
  fracture.
                                             161

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sabath. See hardpan, nari.

safe yield. The amount of water that can be
   safely withdrawn from an aquifer without
   causing undue effects such as aquifer
   depletion.

safe yield of stream.  The lowest dry
   weather flow of a stream[16].

safety line.  A safety rope attached to a
   caver climbing on a ladder or negotiating
   a difficult situation and held by a man
   above'25'.

saline spring. See spring, saline.

saline water. Water that generally is
   considered unsuitable for human
   consumption or for irrigation because of
   its high content of dissolved solids.
   Generally expressed as milligrams per
   liter (mg/L) of dissolved solids, with
   35,000 mg/L defined as sea water,
   slightly saline is 1,000-3,000 mg/L,
   moderately saline is 3,000-10,000 mg/L,
   very saline is 10,000-35,000 mg/L, and
   brine has more than 35,000 mg/L[22].

salinity stratification. The stratification of
   water in estuaries due to salinity-density
   differences'161.

salt dome. A dome-like intrusion of a
   mobile salt core into sedimentary rock[16].

salt karst.  Areas in which karst landforms
   are developed upon halite or halite-rich
   rock, which are generally small and
   limited to arid regions, are referred to as
   salt karst. Except in desert regions,
   dissolution of rock salt occurs in buried,
   interstratal, situations, and the effects of
   such dissolution at the surfacd include
   subsidence pipes or wider subsidence
   areas, such as those represented by the
   meres and 'flashes' in the Cheshire Plain,
   England193.                  |

salt lake.  A lake containing high salt
   concentrations and usually not having any
   outflow[16].                 I
                              I
salt tolerance.  The resistance of crops to
   salt concentration1'61.         !

salt weathering. Detachment of particles of
   various sizes from a rock surface by the
   growth of crystals from salt solutions.
   Forms substantial features in Nullarbor
   Plain caves[25].               ;
                              i
saltation. Solid matter transported by a
   stream by the action of leaping movement
   over the stream bed. See also saltation
   load.                       :

saltation load.  The solid matter; transported
   by streams'161.               '
                              i
saltwater intrusion. The movernent of salt
   water into fresh water aquifers'221.

sampling. The taking of small quantities of
   water or porous media for analysis'161.
                              i
sand. Unconsolidated detrital rock
   material1161.                 i

sand pipe. See solution pipe.

sand stalagmite. A stalagmite formed on
   sand and made of calcite-cemented
   sandstone'101.
                                            162

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sandstone caves. Most natural sandstone
  caves are surface river-cut notches at trie
  foot of rock cliffs, or left part way up the
  cliff due to later downcutting. This origin
  accounts for most of the caves once
  inhabited by the Pueblo Indians in the
  sandstone cliffs of the western USA. True
  caves do occur in sandstone and some  of
  these appear to be at least partially of
  dissolutional origin. Their existence
  probably reflects matrix leaching by
  ground water moving through zones of
  especially high primary porosity and
  permeability.  Though sandstones with a
  calcite matrix cement are more prone to
  such development, even siliceous cement,
  which has a very low solubility in water,
  may be removed during a sufficiently
  long time span. The sandstone  caves of
  the Sarisarinama Plateau, Venezuela may
  be a special case of this type of
  development. These include shafts 300m
  in diameter and 200m deep, and passages
  up to 500m long. They were probably cut
   in the quartz sandstone by underground
   streams, after early leaching of the cement
  by hydrothermal solutions, and the shafts
   have been modified by later collapse191.

 saproplhage.  A scavenger feeding on
   decaying organic material[25].

 saturated.  1. Referring to rock with
   water-filled voids.  2. Referring to water
   which has dissolved as much limestone or
   other karst rock as it can under normal
   conditions'^51.

 saturated  flow.  Single phase flow when all
   voids are filled[16].  Not to be confused
   with chemical saturation.
saturated water. Water which is in
  chemical equilibrium with its enclosing
  media and is thus nonagressive. Water, at
  about 25 °C, in contact with calcite and
  the normal atmosphere, will contain
  approximately 30 to 50 ppm of Ca when
  saturated, variations being mainly due to
  differing j^H.  Determination of the
  saturation point of natural waters is
  complex[20]. Synonyms: (French.) eau
  saturee; (German.) gesattigtes Wafier;
  (Greek.) koresmenon ydor; (Italian.)
  acqua satura; (Spanish.) agua saturada;
  (Turkish.) doygun su; (Yugoslavian.)
  zasicena voda.

saturated zone. See phreatic zone and zone
  of saturation.

saturation regime. A flow regime in
  completely saturated porous medium[16].

saturation, zone of. See phreatic zone and
  zone of saturation.

scale.  1. A very thin and flat rock
   fragment1163. 2. The accumulation of
  precipitated solid material. 3. The ratio of
  prototype to model dimensions. 4. The
  ratio of the length between any two points
   on a map, plan or section to the actual
   distance between the same points on the
   ground or in a cave[251.

scaling chip.  A thin small rather irregular
   piece of limestone, commonly crumbly,
   which has fallen from the ceiling or wall
   of a cave. A  form of cave breakdown1101.

scaling factor.  The ratio of characteristics
   of a model to those of the prototype[16].
                                            163

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scaling plate. A small flat piece of rock of
   rectangular or polygonal shape, that has
   fallen to the floor of a cave. A form of
   cave breakdown in thin-bedded impure
   limestone cut by closely spaced joints'101.

scaling poles. A lightweight metal alloy
   pole, in short sections for transport and
   fastened together where used, to raise a
   ladder to points inaccessible by
   climbing1251.

scallop.  1. A spoon-shaped hollow carved
   in a cave wall, floor or ceiling due to
   erosion by eddies in flowing water.
   Scallops are commonly closely packed,
   leaving sharp ridges at the intersects.
   They range from 10mm to 1m in length
   and as a general rule the smaller they are
 ,  then the faster flowing was the water that
   carved them.  The scallops are generally
   asymmetrical, with their upstream end
   steeper than the downstream end — a
   useful indicator of paleo-flow direction in
   abandoned passages[9]. 2.  Oval hollow
   having an asymmetric cross section along
   its main axis. Scallops form patterns on
   the walls of caves and in streambeds and
   may be used  to determine direction of
   flow of turbulent water, since they are
   steeper on the upstream side. Commonly
   called flutes in America[10]. Synonyms:
   (French.) cannelure, vague d'erosion;
   (German.) in Flieflrichtung des Waflers
   ausgezogener Kolk; (Greek.) kilon o-
   o'ithes; (Spanish.) huella de corriente;
   (Turkish.) degirmi, tarak.  See also flute.

scar.  (Northern England.) Steep rock cliff
   in limestone country often indicating
   outcrop of relatively bare and massively
   bedded limestone[20].  Synonyms:
   (French.) cicatrice, griffure; (German.)
  Klippe; (Greek.) ouli; (Spanish^.) ceja (in
  central Spain); (Turkish.) kirecta^i dik
  yan.

scats.  Animal droppings, an important
  source of food in caves'23].    '

scavenger. An animal that eats the dead
  remains and wastes of other animals and
  plants[23].  See also predator. .

Schichtfugenkarren.  (German.) See
  bedding grike.               :

scholzite. A cave mineral —   i
  CaZn2(PO4)2-2H2O[11].

scour. The erosive action of running water
  in streams'-16'1.

screen, screen pipe.  Slotted well casing
  that is positioned within the producing
  horizon to prevent the inflow of detrital
  particles into a well while allowing the
  inflow of water. See also well screen.

sea cave.  1. A cave cut in any rock type
  where a geological weakness is exploited
  by the highly selective erosion power of
  wave action. Fingal's Cave, cut in the
  basalt of Staffa, Scotland, is a famous
  example. True sea caves should not be
  confused with dissolutional caves that
  pre-dated the wave action but were then
  intersected and revealed as  a cliff line was
  eroded back such as caves in the Chalk at
  Beachy Head in south-east England. In
  some young tropical islands, dissolutional
  voids have formed below sea-level in the
  mixing zone between fresh and saline
  ground water. Some have subsequently
  been tectonically uplifted into a shoreline
  position, to give the misleading
                                            164

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  impression of having developed due to
  waver action. Caves of this type on the
  coast of Tongatapu, Tonga, have pools
  that connect with active dissolutional
  cavities below sea-level that might be
  related to the mixing zone[9].  2. A cave or
  cleft in a sea cliff or coastal karst outcrop
  eroded by waves or currents or dissolved
  by circulating ground water1201.
  Synonyms: (French.) grotte marine;
  (German.) Kustenhohle, Meereshohle;
  (Greek.) thalassion spelson -paraktion
  spelean; (Italian.) grotta marina;
  (Russian.) morskaja pescera; (Spanish.)
  cueva marina; (Turkish.) deniz
  magarasi; (Yugoslavian.) morska
  pecina (spilja). See cave.  Compare nip.
  See also littoral zone.

sea estavelle.  Submarine or sea-shore
  opening in karst formations which at one
  season or period discharges round water
  (fresh or brackish) from the aquifer into
  the sea-bed and at another season or
  period draws seawater into the aquifer by
  a vacuum1201. Synonyms: (French.)
  estavelle marine; (German.) submarine
  Estavelle; (Greek.) estavelle thalassia
   (estavella); (Italian.) Estavella
  sottomarina, sorgente sottomarina a
  flusso alterno; (Spanish.) estavela
   marina; (Turkish.) sahil batar
sea level. The average height of the surface
   of the sea used as a datum for
   elevations1161.

sea-mill. A mill whose motive power is
   derived from the flow of water into (or
   possibly  out of) a sea estavelle; the .
   classical  example is on the Vinaria
   Peninsulas, at Argostolion,
   Kephallinia1201.  Synonyms:  (French.)
   moulin de la mer, moulin d'Argostoli;
  (German.) Meermiihle; (Greek.)
  thalassomylos; (Spanish.) molino de
  mar; (Turkish.) deniz suyu degirmeni;
  (Yugoslavian.) morska vodenica. See
  sea estavelle.

sea ponor. A submarine opening in karst
  formations where seawater flows or is
  drawn by a vacuum into the aquifer1201.
  Synonyms: (French.) perte sous-marine;
  (German.)  submariner Ponor; (Greek.)
  ypothalassia katavothra; (Italian.)
  inghiottitoio sottomarino; (Spanish.)
  sumidero marino; (Turkish.) denizalte
  suyutam; (Yugoslavian.) morska
  vodenica, morskiponor. See ponor.

sea water intrusion.  See saltwater
   intrusion.

sealing-grout, grout. Cement ;grout
   injected between a well casing and the
   borehole wall (annular space) to seal off
   an aquifer from external contamination.

secondary interstices.  Voids formed in a
   rock after  the rock had been formed1161.

secondary porosity.  Porosity created after
   rock formation due to fracturing,
   leaching, etc.

 section.  A plot of the shape and details of a
   cave in a particular intersecting plane,
   called the section plane, which is usually
   vertical1251.

 sediment. Material recently deposited by
    water, ice or wind, or precipitated from
    water^251.
                                             165

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sedimentation. The deposition of solid
   disintegrated rock material by water,
   wind, or gravity transport[I6].

sediment transport. The transport of
   eroded rock material by moving water or
   wind!16'.

seep. 1. An area, generally small, where
   water or oil percolates slowly to the land
   surface.  See seepage and spring[22]. 2. To
   move slowly through small openings  of a
   porous material[22].

seepage. 1. The infiltration or percolation of
   water through rock or soil to or from the
   surface and usually restricted to the very
   slow movement of ground water. 2. The
   fluid discharged at a seep[22]. 3. The
   amount of fluid discharged at a seep[22].
   4. The slow flow  of water through a
   porous medium.  5. The movement of
   water in unsaturated soil[16].

seepage water. See percolation.

seepage face.  A boundary between the
   saturated flow field and the atmosphere
   along which ground water discharges,
   either by evaporation or movement
   'downhill' along  the land surface or in a
   well as a thin film in response to the force
   of gravity1221.

seepage force.  The fractional drag of water
   flowing through voids or interstices in
   rock causing an increase in the
   intergranular pressure (i.e.  the hydraulic
   force per unit volume of rock or soil
   which results from the flow of water and
   which acts in the  direction of flow).
seepage line. 1. The uppermost level at
  which flowing water emerges along a
  seepage face[22].  2. The upper free water
  surface of the zone of seepage.;
  Synonymous with line of seepage,
  phreatic line[22].              '<
                              i
seepage path. The trajectory of fluid
  particles in seepage flow[16].   ;

seepage rate. The rate of seepage fiow[16].

seepage spring; filtration spring. See
  spring, seepage.

seepage surface. The outflow surface
  between water level and the intersection
  of the phreatic surface in a well[16].

seepage velocity. See specific discharge.

selenite.  Blade-like crystals of gypsum[91.
                              i

self-cleaning capacity. The  capacity of a
  river to clean its water of pollutants over a
  given length of water course[16].

selenite needles. A sulfate speleothem
  having the shape of a needle that grows
  from gypsiferous cave soils[I3]: See also
  speleothem.                 :

semiconfined aquifer. See leaky aquifer.
                              i
sepiolite. A cave mineral—    \
  Mg4Si6015(OH)2-6H2Otnl.     \

series. A subdivision of rock according to
  age at which they were laid down in a
  geologic epoch[16].

setting of cement.  The process bf
  hardening of cement[16].       !
                                            166

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settling basin.  A basin used for the settling
   out of solids from suspension1'61.      ;

settling velocity. The terminal velocity at
   which a particle will fall through a
   fluids.

sewage. Domestic and municipal wastes[16].

shaft.  1. Vertical, or steeply inclined,
   sections of a cave passage, of enormously
   varied size. The world's deepest known
   shaft is the entrance shaft of Brezno pod
   Velbom on the Kanin plateau, Slovenia; it
   is 501m deep, with no ledges. Much
   debate surrounds statistics  on the depths
   of fully underground shafts, which may
   be broken by ledges, but among the
   deepest is a shaft about 430m deep in
   Italy's Abisso di Monte Novegno[9].  2. A
   cylindrical tube generally steep sided, that
   forms by'solution and (or)  collapse[IO]. 3.
   A vertical passage in a cave[10]. 4. A
   vertical and usually large diameter hole
   penetrating geologic formations for
   access of subsurface points'161.  See jama,
   karst shaft. See also pit; pothole
   (definition 2.).

 shake; shakehole. (England; sometimes
   spelled shackhole.)  1.  Term used mainly
   by cavers to indicate a doline, especially
   one formed by subsidence. 2. Hole
   formed by solution, subsidence, and
   compaction in loose drift or alluvium
   overlying beds of limestonet101.  3. Small
   subsidence or suffosion doline formed in
   the glacial till overlying limestones in the
   northern Pennies. See jama.

 shall sand.  Sand containing considerable
   amounts of clay and shale[I61.
shawl. Simple triangular-shaped curtain[10].

shear plane. A plane along which failure of
  material occurs by shearing.

shear stress. See stress, shear.

sheet.  A thin coating of calcium carbonate
  formed on walls, shelves, benches, and
  terraces by trickling water1101.

sheet erosion. Erosion occurring over
  widespread tabular sedimentary or
  effusive rock[16].
                             !
sheet jointing. Fracturing of tensile
  character, mostly in granitoid rocks,
  parallel to the land surface.  Sheet jointing
  is developed either by load release or
  temperature differences.

shield; cave shield. 1. A thin circular disc
   of calcite projecting from a cave wall at
   any upward inclination, commonly a
   meter or more in diameter and with the
   underside draped with stalactites and
   curtains. The shield is  actually a double
   disc with a thin central crack that acts as
   the continuation of a wallrock fracture.  It
   grows by water moving up the crack
   under pressure and depositing calcite on
   both sides of its outer rim. Shields are
   rare, but Lehman Cave, Nevada, has more
   than a hundred of them[9]. 2. A
   disk-shaped speleothem standing
   edgewise at a high angle[101. 3. A
   geologically stable and undisturbed
   continental block[I6].

 shilin. A type of pinnacle karst formed on
   low plateau of gently dipping limestone;
   it is distinguished by densely packed
   pinnacles up to 25m high, fluted by sharp
                                             167

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   Rillenkarren.  Known only in southern
   China, shilin (pronounced sherlin)
   translates as stone forest191.

shore. The zone of separation between land
   and moving watert>6].

show cave.  A cave that has been made
   accessible to the public for guided
   visits1*51.

sieve analysis. The determination of the
   particle-size distribution of a soil,
   sediment, or rock by measuring the
   percentage of the particles that will pass
   through standard sieves of various sizes[6].

sieve opening. The opening between the
   mesh wires of a sieve[161.

sieve retention.  The material retained on a
   sieve[16J.

silicate rock.  Rock containing silica in
   predominant proportions1^61.

silicic acid. H4SiO4 monomeric acid[I6].

silicon dioxide.  Silica (SiO2.) See also
   quartz.

Silikatkarren. (German.) Granites and
   related rocks that possess small outcrop
   sculpturing such as rounded runnels.
   They are best developed in the humid
   tropics such as Malaysia181.

silt.  A grain particle with a diameter that
   ranges between 0.005 to 0.05 mm[16].

silting.  The deposition of silt in wells,
   caves, or reservoirs1161.
sima. (Spanish.) Natural well that has
  vertical sides[10].             ;

similarity criteria.  The conditions
  indicating under what circumstances a
  model and prototype are similar[16].

simple hydrograph. A single peaked
  hydrograph[16].               ;

single outlet. A stream cutting through a
  divide (tributary basin) or outflow to the
  sea (major basin)[I6].

single rope technique. The practice of
  climbing up and down ropes with the help
  of ascenders and descenders.  •
  Abbreviation: SRT.          |

sink; sinkhole. (American.)  1. A point
  where a stream or river disappears
  underground. The sinking water may
  filter through a choke that excludes
  cavers, or may flow into an open
  horizontal cave or vertical shaft, and.
  while active all of these may be termed
  sinkholes. The flow of water may be very
  small, but in full flood many sinkholes
  swallow flows of tens of cubic meters per
  second. The character of sink water (or
  swallet water, as it is commonly termed
  by hydrologists), flowing directly and
  rapidly into an open cave, distinguishes it
  from percolation water[9]. 2. General
  terms for closed depressions.  They may
  be basin, funnel, or cylindrical shaped[1°3.
  See also closed depression; ddline; ponor;
  stream sink; sumidero; swallet; swallow
  hole.

sinkhole plain. (American.) Plain on which
  most of the local relief is due to closed
                                            168

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  depressions and nearly all drainage is
  subterranean110].                     *:

sinkhole pond. (American.) Small lake in
  closed depression in limestone, due to an
  impervious clay floor or to intersection of
  depression with the water table[10]. See
  doline lake.

sinking river, sinking stream. A small
  stream that disappears underground^01.
  See also lost river; doline; ponor; sink;
  sinkhole; stream  sink; sumidero; swallet;
  swallow hole.

sinter.  1. A rock or deposit formed by
  precipitation from natural water, often
  from a hot or cold spring.  Calcareous
  sinter is calcium carbonate and is also
  known as tufa, travertine, and onyx
  marble. Siliceous sinter is silica and is
   also known as geyserite and fiorite[20]. 2.
   A mineral precipitate deposited by a
   mineral spring, either hot or cold.
   Siliceous sinter,  consisting of silica, may
   be called geyserite and fluorite; cal-
   careous sinter, consisting of calcium
   carbonate, may be called tufa, travertine,
   and onyx marble[10].  Synonyms: (French.)
   concretion; (German.) Sinter, Kalktuff,
   Travertin; (Greek.) asvestolithikos
   toffos; (Italian.) concrezione; (Russian.)
   oilozenija istocnikov; (Spanish.)
   concrecion; (Turkish.) kaynak tiifti;
   (Yugoslavian.) travertin, sedra, bigar,
   lehnjak. Related to travertine.

 siphon. 1. Synonym for a sump, or a'section
   of flooded cave  passage, in common
   parlance. True siphons, where water
   flows first up and then down are rare in
   caves, as the fractures in limestone tend
   to disrupt the required hydraulics.  They
   are, however, the origin of such
     intermittent springs as the Fontestorbes
     spring in France, and the Ebbing and
     Flowing Well at Giggleswick Yorkshire.
     Both flow in regular pulses when the
     siphon is full and working, only to cease
     when the siphon input is broken by air, as
     the upstream reservoir level drops.  Their
     operation depends on critical flows and
     both operate only in favorable weather
     conditions191. 2. Gallery in form of an
     inverted 'U' with water moving only
     under pressure when the siphon has
     completely filled up; the water head at the
     input end being higher than at the
     drainage point[20].  3. In speleology, a cave
     passage in which the ceiling dips below a
     water surface[10].  Synonyms; (French.)
     siphon; (German.) Siphon; (Greek.)
     siphon; (Italian.) sifone; (Russian.) sifon;
     (Spanish.) sifon; (Turkish.) sifon;
     (Yugoslavian.) sifon, smrk.  See also
     water trap.

   site characterization.  Means the program
     of exploration and research, both in the
     laboratory and in the field, undertaken to
     establish the geologic conditions and the
     ranges of those parameters relevant to a
     particular site.  Site characterization
     includes borings, surface excavations,
     excavation of exploratory shafts, limited
     subsurface lateral excavations and
     borings, and in situ testing at depth
     needed to  determine the suitability of the
      site for a geologic repository, but does not
     include preliminary borings and
      geophysical testing needed to decide
      whether site characterization should be
      undertaken[22].

    skin effect.  The effect of the zone of
      reduced permeability immediately around
169

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   the borehole on transient flow phenomena
   in pumping tests[16].

skrytyi karst, zakrytyi karst. (Russian.)
   See closed karst.

skylight. A hole in the roof of a cave
   passage through to the ground surface. It
   may be an inlet shaft, a section of
   collapse or a breach due to surface
   lowering191.

slickenside. 1. A polished, commonly
   striated rock surface within a fault plane,
   produced due to friction during fault
   movement. The striae give an indication
   of the fault movement direction'91. 2. A
   polished fault plane with grooves due to
   relative motion of fault blocks'161.

sliding. 1. The relative displacement of two
   bodies along a surface, without loss of
   contact between the bodies. 2. The
   downslope movement of rock and earth
   material1161.

sling. A joined loop of rope or tape'251.

stacker. Local term used in the  eastern
   Mendip Hills, England for a swallet or
   stream sink[9].

slope. The inclination of a surface'161.

slump pit.  A hollow in the clay fill of a
   cave floor caused by erosion beneath the
   fill™.

smithsonite. A cave mineral — ZnCO3'ul.

snow. Solid crystalline form of water'161.
snow cover; snowpack. The accumulated
  height of snow covering a given area[16].

snow line.  A line connecting elevations
  above which snowpack remains
  throughout the year'161.

snow sampler. A tube used for the taking
  of cylindrical snow samples through a
  snow profile'161.

snowdrift.  Snow accumulation due to wind
  transport'161.                 i
                              i

sod. Root system in a soil'161.

soda straw. 1. Proto-stalactite in which
  water flow down through the center of the
  straw. Upon entering a vadose cave
  passage, the change in the partial pressure
  of carbon dioxide cause CO2 degassing
  and the slow precipitation of CaCO3. The
  straw grows downwards as a result; water
  also flows down the outside of the straw
  causing the stalactite to grow outwards
  around the straw. 2.  American name for
  straw stalactite'91.            ;

soddy karst.  See subsoil karst.

sodium.  A naturally occurring element
  (Na).                       ;

soil aggregate. Loosely cemented cluster of
  soil particles'161.              !

soil air.  The air that fills soil and rock
  interstices above the  zone of saturation'101.

soil bulk density.  The mass of dry soil per
  unit bulk soil'221.             ;

soil-covered karst. See subsoil karst.
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soil mechanics.  The science of dealing with
  the mechanical properties of soils[16].  v

soil moisture. Subsurface liquid water in
  the unsaturated zone expressed as a
  fraction of the total porous medium
  volume occupied by water.  It is less than
  or equal to the porosity1221.

soil-moisture meter.  A device used to
  record soil moisture in situtl6].

soil-moisture suction. The negative pore
  pressure exerted by capillary forces[1<51.

soil profile. A vertical section of the soil
  mantle usually with distinguishable soil
  horizons'161.

soil sample.  A sample of soil  on which soil
  properties are to be determined'161.

soil swelling.  The volume increase of soil
  due to swelling of unsaturated clay
  particles when in contact with water'161.

soil water. See soil moisture.

soil-water pressure.  The pressure (positive
  or negative), in relation to the external
  gas pressure on the soil water, to which a
  solution identical in composition with the
  soil water must be subjected in order to
  be in equilibrium through a porous
  permeable wall with the soil water'221.

soilcover. A layer of soil material covering
  bedrock[16].

soilwater zone. The upper portion of the
  zone of aeration containing soil water'161.
solid matrix. An assembly of
  interconnected solid mineral grains
  surrounded by voids'161.

solid volume. The volume of solid particles
  in a porous sample'161.

solifluction.  The slow flowage of mud
  streams in arctic regions.

solubility.  The total amount of solute
  species that will remain indefinitely in a
  solution maintained at constant
  temperature and pressure in contact with
  the solid crystals from which the solutes
  were derived'221.

solum.  The top layers of a soilprofile'161.

solute.  The substance present in a solution
  in the smaller amount. For convenience,
  water is  generally considered the solvent
  even in 'concentrated' solutions with
  water molecules in the minority1223.

solute transport.  The net flux of solute
  through  a hydrogeologic unit controlled
  by the flow of subsurface water and
  transport mechanisms'221.

solution.  1. Synonym for dissolution,
  except that the product of the solution (or
  dissolution) process, is also termed a
  solution,-this being a combination of
  liquid and non-liquid (solid or gaseous)
  components that exists as a liquid'91.  2. A
  homogeneous mixture of two or more
  components. In ideal solutions, the
  movement of molecules  in charged
  species are independent of each other; in
  aqueous solutions charged species interact
  even at very low concentrations,
  decreasing the activity of the solutes[22].
                                             171

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  4. The change of matter from a solid or
  gaseous state to a liquid state by
  combination with a liquid[IO]. 5. The
  result of such change; a liquid
  combination of a liquid and a nonliquid
  substance[10J. See corrosion.

solution breccia. A mass of rock composed
  of angular to rounded fragments of rock
  that have accumulated by solution of
  surrounding or underlying carbonate. See
  also collapse breccia.

solution flutes. See rillenkarren.

solution lake. A lake whose origin is
  attributed largely to solution of under-
  lying rock.

solution notch. These form wherever
  humic soil borders on a very steep or
  vertical limestone surface.  The rock
  becomes undercut by water rich in
  biogenic CO2. In the cone karst of the
  humid tropics, foot caves occur which are
  over-sized enlargements of solution
  notches'-3-1.

solution pan. Shallow solution basin or
  closed depression formed on bare
  limestone, generally characterized by flat
  bottom and overhanging sides[10]. The
  initial form is a closed hollow created by
  a humus patch. It may have over-hanging
  side walls and a flat floor covered by
  algae and small pieces or broken rock.  •
  Diameters are rarely greater than 15 cm[3].
  Synonyms: (German.) Kamenitza or
  Kamenica, opferkessel; (British.) panhole;
  (Spanish.) tinajita.  See Kamenica.

solution pipe. A vertical cylindrical hole
  attributable to solution, often without
  surface expression, filled with; debris,
  such as sand, clay, rock chips, !and
  bones[10].  Synonym: sand pipe.  See also
  geologic organ.              ;

solution runnel. See Rinnenkarren.

solution scarp. Escarpment formed by
  more active solution of lower area or by
  corrosional undercutting of the base of the
  escarpment[10).

solution subsidence. 1. Any subsidence
  due to solution of underlying rock but
  particularly the subsidence of barts of a
  formation into hollows or pockets of an
  immediately underlying soluble
  formation1101. 2. A crater-like doline in
  rock other than karst limestone, formed
  by surface subsidence above sblutionally
  enlarged fissures in a sub-surface karst
  limestone stratum[19].  Synonyms:
  (French.) affaissementpar dissolution;
  (German.) Losungstaschen,   .
  Losungstrichter; (Greek.) katakdthisma
  thid thialiseos; (Italian.) subsidenza per
  dissoluzione, subsidenza per
  suberosione; (Russian.) prosedanie
  vsledstvie rastvorenija', (Spanish.)
  subsidencia por disolucion; (Turkish.)
  crime algahmi; (Yugoslavian.;)
  korozivno urustvanje.        \

sonar. A system for detecting obstacles by
  emitting sound and intercepting and
  interpreting echoes that bounce back.  It is
  used by bats and also by oilbirds and
  some swiftlets when they fly in the
  darkness of caves[23].

sorption. 1. A general term used to
  encompass the process of absorption and
  adsorption[22]. 2. All processes which
  remove solutes from the fluid'phase and
                                            172

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 . concentrate then on the solid phase of the
  medium[22].

sotano. (Spanish for cellar or basement.)
  Term used in Mexico for deep vertical
  shafts in limestone, which may or may
  not lead to a cave'101.

spangolite.  A cave mineral —
  Cu6Al(S04)(OH)12-3H20[11].

species (singular or plural). A group of
  plants or animals whose members breed
  naturally only with each other and
  resemble each other^more  closely than
  they resemble members of any similar
  group'231.

specific capacity.  The rate of discharge of
  water from a well per unit of drawdown.
  It is commonly expressed  as gpm/ft or
  m3/day/m and varies with pumping test
  duration'61.

specific conductance.  A measure of the
  ability of water to  conduct an electrical
  current expressed in micromhos per
  centimeter at 25°C[22].

specific discharge. The rate of discharge of
  ground water per unit area of a porous
  medium measured at right angle to the
  direction of flow.  Synonyms: Darcy
  velocity; seepage velocity.

specific drawdown. The amount of
   drawdown per unit discharge in a well'161.

specific gravity.  The weight of a particular
  volume of water that a given body of rock
   or soil will hold against the pull of gravity
   to the volume of the body itself.  It is
   usually expressed as a percentage'61.
specific retention, water retaining
  capacity. The ration of the volume of
  water that a given body of rock or soil
  will hold against the pull of gravity to the
  volume of the body itself.  It is usually
  expressed as a percentage'61.'

specific storage. The volume of water
  released from or taken into storage per
  unit volume of the porous medium per
  unit change in head'61.

specific surface. The ratio of grain particle
  surface to the volume of grain particles'161.

specific yield. The ratio of the volume of
  water that a given mass of saturated rock
  or soil will yield by gravity to the volume
  of that mass.  This ratio is stated as a
  percentage'61.

spelean. Of, pertaining to, or related to
  caves'101.

speleogen. A secondary cave structure
  formed by dissolving, such as a dome pit
  or a scallop'101.

speleogenesis. Although the term literally
  means the birth, origin or mode of
  formation of caves, the full extent of
  speleogenesis includes all the changes
  that take place between the inception and
  the eventual destruction of an
  underground drainage system. It includes
  development phases during which the
   active drainage voids are too small to be
  considered caves as normally defined, as
  well  as phases when the cave no longer
   functions as a drain, is enlarging only by
   collapse and,  eventually, is being totally
   removed'91.
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speleogenetics. The totality of all processes
  which effect the creation and
  development of natural underground
  cavities. These comprise corrosion,
  erosion, and incasion, but are also
  influenced by lithology, tectonics, and
  climate.

speleologist. 1. A scientist engaged in the
  study and exploration of caves, their
  environment, and their biota[10].  2.
  Explorer of caves, caverns, and other
  underground openings especially in karst.
  Caver and potholer are slang terms[20].
  Synonyms: (French.) speleologue;
  (German.) Hohlenforscher, Speldologe;
  (Greek.) speleologos; (Italian.)
  speleologo; (Russian.) speleolog;
  (Spanish.) espeleologo; (Turkish.)
  speleolo, magarabilimci; (Yugoslavian.)
  speleolog, spiljar.jamar.

speleology. 1. Scientific study of caves,
  including aspects of sciences, such as
  geomorphology, geology, hydrology,
  chemistry and biology, and also the many
  techniques of cave exploration[9]. 2. The
  scientific study, exploration, and
   description of caves, cave organisms, and
  related features1101. 3. The branch of
   knowledge dealing with the study and
   exploration of underground caves[20]. 4.
   Study, exploration, and description of
   caves, caverns, and other underground
   cavities in karst and rarely in lavas or
   ice1201. Synonyms: (French.) speleologie;
   (German.) Hohlenforschung,
   Hohlenkunde;  (Greek.) speleologhia;
   (Italian.) speleologia;  (Russian.)
   speleology a; (Spanish.) espeleologia;
   (Turkish.) speleoloji, magarabilim;
   (Yugoslavian.) speleologija,
  pecinarstvo, jamarstvo.
speleothem.  1. General term for all cave
  mineral deposits, embracing all
  stalactites, flowstone, flowers, etc. Most
  are formed of calcite whose precipitation
  processes, related mainly to carbon
  dioxide levels in the water, are the direct
  reverse of the dissolution of limestone.
  Climatic influences on dissolution
  processes ensure that speleothems are
  generally larger and more abundant in the
  caves of the wet tropics, which are
  typified by thick stalactites and massive
  stalagmites, in contrast to the straws and
  flowstones of alpine caves[9]. 2.  General
  term for stalactites, stalagmites,
  moonmilk, helictites, and other secondary
  mineral deposits in caves and cavems[20].
  3. A secondary mineral deposit formed in
  caves, such as stalactite or stalagmite1101.
  Synonyms: (French.) concretions
  cavernicoles; (German.)
  Hohlenformation; (Greek.)
  speleolithoma; (Italian.) concrezione;
  (Russian.) natecnia obrazovanija;
  (Spanish.) concrecion (estalagmitica o
  estalactitica); (Turkish.) magqra
  olu$ugu; (Yugoslavian.) sige. •• See also
  cave formation.

spelunker.  See caver.

spelunking. See caving.

spencerite.  A cave mineral —
   Zn4(P04)2(OH)2-3H2Qt11].    j

sphalerite.  A cave mineral — ZnS[11].

spillway. A device that allows for the
   escape of excess water[16].
                              i
Spitzkarren. (German.) These are isolated
   projections that may be of a beehive form
                                             174

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  or may be sharply pointed and tend to lie
  between grikes and the strike ribs of  *
  bedding grikes[8]. See also grike; bedding
  grike; clint.

Spitzkegelkarst.  (German.) Tropical karst
  topography containing sharply pointed
  residual limestone hills[10].

splash cup.  The shallow concavity in the
  top of a stalagmite[10].

spongework.  1. Randomly shaped cavities
  created by undirected phreatic dissolution
  in a massive, essentially homogeneous
  limestone. Fine examples occur in
  Carlsbad Caverns, New Mexico[9]. 2. An
  arrangement of partitioned depressions
  found in cave ceilings and walls, and
  attributed to the differential  solution of
  submerged karst limestones. Larger and
  more isolated hollows are known as
   
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spring, boiling.  1. An uncommon type of
  vauclusian spring, where the flow is large
  enough in a constricted site to form.
  turbulence on the surface of the
  resurgence pool[9]. 2. (Jamaican.) A.
  variable-discharge artesian spring in
  which hydrostatic pressure is great
  enough to cause a turbulent or even
  fountain-like discharge1191. See also blue
  hole.

spring, boundary.  A spring located at the
  boundary between a permeable formation
  overlying an impermeable substratum[16].
                                   .[10]
spring, cave. A spring rising in a cave1
spring, contact. A spring formed at the
  intersection of the land surface and a
  permeable water-bearing formation
  overlying a less permeable formation1161.

spring, depression. A spring originating at
  the intersection of the land surface with
  the water table[16].

spring, drowned. A spring which continues
  to function as a spring after it has become
  submerged by rising sea or lake levels or
  by subsidence of the ground[20].
  Synonyms: (French.) source sous-
  aquatique, source noye; (German.)
  submarine Quelle, sublacustre Quelle;
  (Greek.) vethisthesa pigi; (Italian.)
  sorgente sornmersa; (Russian.)
  subakvaljnij istocnik; (Spanish.) fuente
  subacuatica; (Turkish.) batik kaynak;
  (Yugoslavian.) potopljen izvor,
  potopljeno vrelo, potopljen izvir  (vrelec).
  Related to spring, sublacustrine, spring,
  submarine.
spring, ebb-and-flow; ebbing-and-flowing
  well. A spring (flowing well or borehole)
  exhibiting periodic variation in volume of
  flow; this variation, which may be regular
  or irregular, is often attributed in karst
  regions to siphonic action. Ebb-and-flow
  springs differ from intermittent springs
  because the latter can be related to
  seasonal variations in rainfall[20].
  Synonyms: (French.) source intermittente;
  (German.) intermittierende Quelle;
  (Greek.) pighi ambotidos kai palirrias;
  (Italian.) sorgente carsica intermittente;
  (Russian.) sifonnij istocnik; (Spanish.)
  manatial intermittente, fuente i
  intermittente; (Turkish.) sogultkan kaynak;
  (Yugoslavian.) periodicni ixvor, periodic
 ~ni izvir. See also spring, periodic.  Related
  to intermittent spring.        :

spring, drowned. A spring which continues
  to function as a spring after it has been
  submerged by rising sea or lake levels or
  by subsidence of the ground[201.
  Synonyms: (French.) source sous-
  aquatique, source noye; (German.)
  submarine Quelle, sublacustre Quelle;
  (Greek.) vethisthesa pigi; (Italian.)
  sorgente sommersa; (Russian.)
  subakvaljnij istocnik; (Spanish.) fuente
  subacuatica; (Turkish.) batik kaynak;
  (Yugoslavian.) potopljen izvor, potopljeno
  vrelo, potopljen izvir (vrelec). Related to
  sublacustrine spring, submarine spring.

spring, fracture. A spring with its outflow
  openings consisting of fractures1161.

spring, fullflow. A spring that is the sole
  drain of an area.

spring, gravity.  A spring flowing as a
  result of gravity1161.
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spring head alcove.  The arcuate cliff
  surrounding many risings, formed by tl
  progressive headward sapping and cavern
  collapse. The rapidity of their formation
  is increased by the cliff-line which
  frequently exists already at the lower
  margin of the karst area[19].

spring, intermittent. 1. A karst spring with
  a pulsating flow, caused by the presence
  within the rock of cavities and siphons
  fed by a subterranean watercourse. When
  the cavity is full, the siphon is complete
  and causes a pulse of water to issue from
  the spring. This diminishes or empties
  the water supply in the cavity and no
  further water is discharged from the
  spring until the system is reactivated. The
  discharge is said to be a reciprocating
  spring when a reduced level of flow is
  maintained between pulses[19]. 2.  A
  spring flowing at irregular intervals1'61.
  Synonyms: (French.) source temper aire,
  source intermittent?, (German.)
   intermittierende Quelle, periodische
   Quelle; (Greek.) thialepousa pege;
   (Italian.) sorgente temporanea, sorgente
   intermittente; (Russian.)
  peremezajuscijsja istocnik; (Spanish.)
  fuente intermitente, fuente temporal',
   (Turkish.) kesintili kaynak;
   (Yugoslavian.) periodicko vrelo,
  potajnica, obdobni izvir.  Related to
   spring, ebb-and-flow; spring, periodic.

 spring, karst.  A spring emerging from
   karstified limestone[10]. See also
   emergence; exsurgence; resurgence; rise.

 spring, medicinal. A  spring with healing
   properties^161.

 spring, mineral. A spring having a high
   mineral content.
spring, overflow. A spring that is part of a
  distributary but which drains only at the
  level above base flow.

spring, perched karst. The emergence of
  underground water some where above the
  basement of a calcareous massif caused
  by the interbedding of an impermeable or
  intermittent perched water table by
  restricting the vertical movement of
  water, which instead issues from the
  contact1191.

spring, perennial.  Stream flowing above
  land surface throughout the year[16].

spring, periodic. A spring that shows
  variation in flow that is either regular or
  irregular. It may be due to siphonic
  action1201. Synonyms: (French.) source
  periodique; (German.) Periodische
  Quelle, intermittierende Quelle; (Greek.)
  periodhiki piyi; (Italian.) sorgente
  periodica; (Spanish.) fuente periodica;
  (Turkish.) periyodik kaynak;
   (Yugoslavian.)periodicini izvor (izvir).
   See ebb-and-flow spring.  Related to
   intermittent spring.
                            \
spring, saline. Spring water having a high
   salt content[16].

spring, seepage. A spring where surface
   discharge occurs from numerous small
   openings1161. Synonym: filtration spring.

spring, subaqueous. A spring that
   discharges below the surface of a water
   body (e.g. ocean, lake, rivers  or stream)1161.

spring, sublacustrine. A spring emerging
   in the bed of a lake predominantly in karst
   areas1201. Synonyms: (French.) source
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   sous lacustre; (German.)
   Unterwqflerquelle, sublacustre Quelle;
   (Greek.) ypovrichios pighi; (Italian.)
   sorgente sublacustre; (Russian.) istocnik
   na due ozera; (Spanish.) fuente
   sublacustre; (Turkish.) golalti kaynagi.
   See spring, drowned.

spring, submarine. 1. A spring emerging
   in a sea or lagoon predominantly in karst
   terranes. This is a descriptive term
   generally corresponding to the genetic
   term "drowned spring1201.'  2. Large
   offshore emergence, generally from
   cavernous limestone, but in some areas
   from beds  of lava[10].  Synonyms:
   (French.) source sous marine; (German.)
   Untermeeresquelle, Grundquelle,
   submarine Quelle; (Greek.) ypoihalassia
  pighi;  (Italian.) sorgente sottomarina;
   (Russian.)  submarinnij istocnik;
   (Spanish.)_/we«fe submarina;  (Turkish.)
   denizalti kaynagi; (Yugoslavian.) vrulja.
   See spring, drowned.

spring, thermal. A spring with temperature
   of the  spring water above the  average
   temperature of superficial rock[16].

spring, tubular. A spring issuing from a
   round  channel such as a tubular
   passagetl6].

spring, unconformity. A spring issuing at
   the'contact of an aquifer with an
   unconformity.

spring, underflow.  A spring that is part of
   a distributary but which is at lower
   elevation and preferentially drains base
   flow.  Between it and  an overflow spring
   there may be several underflow-overflow
   springs.
spring, valley.  Springs occurring at valley
   sides where the water table intersects the
   land surface.                 ;

spring, vauclusian; rising, vauclusiau.  1.
   A type of rising or spring where direct
   drainage from the phreas flows up a
   flooded cave passage under pressure to
   emerge in daylight. The term is best
   applied where water rises from a vertical
   or very steep  bedrock passage.; Such
   risings are named after the Fontaine de
   Vaucluse in southern France.  The River
   Sorgue rises from the Fontaine with a
   mean flow of 26 cubic meters per second.
   Its upper part is steeply inclined, but a
   depth it is vertical. A diver has reached a
   depth of—200m, and a robot reached
   —243m, below which the flooded shaft
   continues193.  2. Large karst spring (name
   by Fournet, after la Sorgue en Vaucluse,
   France) characterized by a stream surging
   up as from a siphon. Also applied to
   karst springs  with artesian    j
   characteristics1201. 3. A large spring or
   exsurgence of an underground river, gen-
   erally from limestone, that varies greatly
   in output and is impenetrable except with
   diving apparatus'101. Synonym:
   (American.) gushing spring; (French.)
   source vauclusienne, bouillidou (South
   of France); (German.) Vauclusequelle,
   (Riesenquelle); (Greek.)      ;
   kephalari/vauclusiana pighi; (Italian.)
   sorgente valchiusana; (Russian.)
   vokljuz; (Spanish.) fuente vauclusiana,
   ojo, heryidero; (Turkish.) basincch
   kaynak; (Yugoslavian.) voklisko vre'lo,
   obrh. See also gushing spring.

squeeze.  A narrow passage or opening just
   passable with effort. Differs from
   flattener in that there is little spare space
   in any direction1101.
                                           178

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staff gage. A fixed graduated scale[16].
                                     '^»-
stage.  Water surface elevation at a point
   along a stream, river, lake, etc., above an
   arbitrary datum[16].

stage-discharge relation. See rating curve.

stage hydrograph. The elevation of stage
   plotted against time1161.

stage record. Stage discharge relations
   presented in tabulated form[161.

stagmalite. A general term including sta-
   lactite and stalagmite.  Superseded by
   dripstone1101.

stagnation point. The foremost point on a
   streamline dividing an area of pumping
   depression from a zone of influence in a
   tilted aquifer being pumped by a well[16].

stalactite. 1. Speleothem, generally of
   calcite, formed by  dripping water and
   hanging from a cave roof. Stalactites
   embrace an enormous variety of sizes and
   shapes. They form where percolation
   water seeps from a cave ceiling and
   becomes saturated with respect to calcite
   due to loss of carbon dioxide into the
   cave air. Calcite is precipitated round the
   rim of the water droplet and continued
   deposition creates  a hollow tubular straw
   stalactite (soda straw). Additional
   deposition of calcite on the outside of the
   initial cylinder creates an ordinary
   tapering stalactite.  Almost infinite
   variation in shape  may be influenced by
   changes in water flow, cave air chemistry,
   evaporation, temperature or dissolved
   impurities, and by crystal growth
   blocking flow paths.  They are the most
  common speleothem. Though the single
  7m long stalactite in Ireland's Poll an
  lonain is not the world's longest, it is
  uniquely spectacular against the dark
  chamber walls[9].  2. Conical'deposit of
  calcite or aragonite often with a hollow
  center hanging from the roof of a cave or
  cavern formed by precipitation of
  carbonate due to escape of CO2 from
  hanging water beads and to evaporation
  of part of the water[20].  3. A cylindrical or
  conical deposit of minerals, generally
  calcite, formed by dripping water,
  hanging from the roof of a cave, generally
  having a hollow tube at its center. From
  Greek word meaning exude drops[10].
  Synonyms: (French.) stalactite;
  (German.) Tropfstein, Stalaktit; (Greek.)
  stalaktitis; (Italian.) stalattite; (Russian.)
  stalaktit; (Spanish.) estalactita;
  (Turkish.) sarkit (Yugoslavian.) mosur,
  vised kapnik, stalaktit.

stalagmite. 1. Speleothem, normally of
  calcite, formed by upward growth from a
  cave floor, and therefore the complement
  of a stalactite. Stalagmites form when
  dripwater that is still saturated falls from
  a cave roof or stalactite and, when or after
  it lands, loses more carbon dioxide to the
  cave air, causing precipitation of calcite.
  They vary in size and shape, from tall thin
  towers to wide domes that grade into
  flowstone, the main controls being drip
  rate and height,  and saturation levels of
  the water.  The stalagmites of Aven
  Armand, France, are of the multiple
  splash-cup variety while being notably
  slender and up to 30m tall. Spectacularly
  massive stalagmites occur in the Carlsbad
  and Cottonwood Caves of >few Mexico[9].
  2. Columnar or partly irregular deposit of
   calcite or aragonite on the floor of a cave
   or cavern formed by the precipitation of
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  carbonates due to escape of CO2 from
  water dripping from the roof1201. 3. A
  deposit of calcium carbonate rising from
  the floor of a limestone cave, formed by
  precipitation from a bicarbonate solution
  through loss of CO2. The water drops on
  the stalagmite from above. From Greek
  word meaning drip[10].  Synonyms:
  (French.) stalagmite; (German.)
  Bodenzapfen, Stalagmit; (Greek.)
  stalagmitis; (Italian.) stalagmite;
  (Russian.) stalagmit; (Spanish.)
  estalagmita;  (Turkish.) dikit;
  (Yugoslavian.) oulak, stojeci kapnik,
  stalagmit.  See also dripstone.

stalagmite, capillary. See capillary
  stalagmite.

standard deviation. A measure of
  variability of the square of individual
  deviations from their mean[16].

standing line. A rope of approximately
  0.4375 inches or 11 mm in diameter that
  is tied to a solid anchor and is used for
  descending and ascendingtI3].  See also
  ascender; knot; mechanical ascender;
  prusik knot; prusiking.

state of solution. The degree to which a
  mineral or rock has gone into solution[16].

static head. See head, static.

static water level.  The level of water in a
  well that is not being affected by
  withdrawal of ground water[6].

station.  A survey point in a chain of such
  points in a survey1251.
steady flow. Flow where the velocity ait a •
  point remains constant with respect to
steam hole.  An opening from a cavity
  through which a current of air charged
  with vapor blows upwards and condenses
  at the orifice to appear as steam.  Such
  openings are an occasional feature in
  karst terranes[20].  Synonyms: (French.)
  puits a vapeur, puitsfumant; (German.)
  Dampfschlot; (Greek.) atmotrypa;
  (Spanish.) cavidad fumante; (Turkish.)
  buhar deligi.

steep. The property of inclination with a
  very steep gradient1 16].

steephead. A deeply cut valley, generally
  short, terminating at its upslope end in an
  amphitheater, at the foot of which a
  stream may emerge[10].        ;

stegamite.  A speleothem projecting
  upwards from a cave floor in the form of
  a calcite ridge.  A medial crack appears
  along the top of the ridge where water is
  thought to be forced from the speleothem
  under capillary action[25].

stemflow. Rain water flowing down the
  stem of plants[16].            ;

stereo aerial photographs. Aerial
  photographs shot in sequence over a
  landscape so that when adjoining photos
  are viewed at the proper interpupillary
  spacing, features may be seen in three-
  dimensions.

stereogram. A block diagram or three-
  dimensional diagram1161.      :
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stilling well. A well connected to a flowing
   stream or spring through a bottom conduit
   permitting elevation measures to be taken
   in quiescent water[16].

stomatal transpiration. The transpiration
   by escape of water through pores
   (stomata) of leaves[16].

stone forest.  See shilin.

stoping. The upward migration of the
   ceiling in a passage or room by the action
   of slabs falling[13].

storage capacity. 1. The ability of an
   aquifer to store water[16].  2. The capacity
   of rivers to store water in their own
   channel[16].

storage coefficient. 1. The volume of water
   an aquifer releases from  or takes into
   storage per unit surface area of the aquifer
   per unit change in head[22].  In a confined
   aquifer, the water is derived from storage
   with decline in head resulting from an
   expansion of the water and compression
   of the aquifer. Similarly, water added to
   storage with a rise in head is
   accommodated partly by compression of
   the water and partly by expansion of the
    aquifer. In an unconfined aquifer, the
    amount of water so released or accepted
    is generally negligible compared to the
    amount involved in gravity drainage or
    filling of pores, hence, in an unconfined
    aquifer, the storage coefficient is virtually
    equal to the specific yield.  2. The volume
    of water an aquifer releases from or takes
    into storage per unit surface area of the
    aquifer per unit change  in head (virtually
    equal to the specific yield in an
    unconfined aquifer.) 3. The volume of  •
  water a confined hydrogeologic unit
  releases from or takes into storage per
  unit subsurface area of the hydrogeologic
  unit per unit change in head.

storage gage. A precipitation gage for
  collecting and storing the total amount of
  inflowing water to be read at long
  intervals1161.

storage in depressions. Waterretention in
  surface depressions[16].

storativity. See storage coefficient.

storm. 1. A disturbance of average
   meteorological conditions and usually
   connected with precipitation[16]. 2. A
   period of precipitation over a specific
   drainage basin[16].

strath terrace. An erosional remnant of an
   elevated broad river valley1161.

stratification. 1. A depositional structure of
   sedimentary rocks in beds and layers[161.
   2. The separation into non-discrete layers
   of water as a result of chemical, saline, or
   temperature differences which in turn
   create density differences in the water.

 stratigraphic column. A graphic means of
   representing the various rock types of an
   area in a geologic report[131.

 stratigraphic sequence. The sequence  of
   rock types in an area[13].

 stratum. A sedimentary bed or layer[16].

 straw stalactite; straw.  1. The simplest
    form of stalactite — a fragile, thin walled
    tube, normally of calcite, which is the
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  diameter of the drops of water that hang
  from its end and continue its growth.
  Though only aboutSmm in diameter,
  straw stalactites (or straws) may grow to
  great length in clusters of spectacularly
  dense profusion, more commonly in caves
  of cooler climates. The length record
  may be held by a 6m straw in Easter
  Cave, Western Australia. Also known as
  straw stalactite or soda straw[9].  2. Thin
  tubular stalactite, generally less than a
  centimeter in diameter and of very great
  length (examples as long as 4 meters);
  also called soda straw[I01. See also soda
  straw; stalactite.

stream. A body of flowing water[16].

stream bed.  The bottom of a stream
  covered by water[16].

stream development. The ratio of actual
  tortuous stream length between two
  points on a straight line connecting these
  points1161.

stream flow. The total runoff confined in a
  stream and its' channel[16].

stream frequency. Channel frequency; the
  number of stream segments per unit
  area™.

stream order. The hierarchic order of
  stream segments according to
  tributaries1163.

stream profile.  The elevation of the main
   stream bed as a function of distance from
   outflow.

stream sink, streamsink.  Point at which a
   surface stream sinks into the ground[101.
  See also doline; ponor; sink; sinkhole;
  sumidero; swallet; swallow hole.

stream tube. 1. A cave passage completely
  filled, now or in the past, with fast-
  moving water and whose ceiling and
  walls normally show scallops[10]. 2. The
  imaginary space formed between two
  adjacent streamlines in which flow is
  constant (assuming steady flow
  conditions). Synonyms: (French.)
  conduite forcee; (German.)
  Druckflufirohr; (Greek.) ypoghios
  siranx; (Italian.) condotta forzata;
  (Spanish.) tubo (o conducto) freatico;
  (Turkish.) akarsu mecrasi. See conduit,
  pressure flow tube.

streamline.  A curve that is everywhere
  tangent to the specific discharge vector
  and indicates the direction of flow at
  every point in a flow domain.

streamtube. A cave passage completely
  filled, or formerly filled, with fast-moving
  water and whose ceiling and walls
  normally possess scallops1101.

strength.  The maximum stress which a
  material can resist without failing for any
  given type of loading.

stress. The  force acting across a given
  surface element divided by the area of the
  element.

stress, applied.  The downward stress
  imposed at an aquifer boundary. It differs
   from effective stress in that it defines only
  the external stress tending to compact  a
   deposit rather than the grain-tp-grain
   stress at any depth within  a compacting
   deposit1211.

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stress, effective. Stress (pressure) that is
   borne by and transmitted through the  ,.
   gram-to-grain contacts of a deposit, and
   thus affects its porosity or void ratio and
   other physical properties. In one-
   dimensional compression, effective stress
   is the  average grain-to-grain load per unit
   area in a plane normal to the applied
   stress. At any given depth, the effective
   stress  is the weight (per unit area) of
   sediments and moisture above the water
   table,  plus the submerged weight (per unit
   area) of sediments between the water
   table and the specified depth, plus or
   minus the seepage stress (hydrodynamic
   drag) produced by downward or upward
   components, respectively, of water
   movement through the saturated
   sediments above the specified depth.
   Thus,  effective stress may be regarded as
   the algebraic sum of the two body
   stresses, gravitational stress, and seepage
   stress.  Effective stress mal also be
   regarded as the difference between
   geostatic and neutral stress[21].

stress, geostatic. The total load per unit
   area of sediments and water above some
   plane of reference. It is the sum of (1) the
   effective stress, and (2) the neutral
   stress1213.

stress, neutral. Fluid pressure exerted
   equally in all directions at a point in a
   saturated deposit by the head of water.
   Neutral pressure is transmitted to the base
   of the  deposit through the pore water, and
   does not have a measurable influence on
   the void ratio or on any other mechanical
   property of the deposits[21].

stress, preconsolidation.  The maximum
   antecedent effective stress to which a
   deposit has been subjected, and which it
   can withstand without undergoing
   additional permanent deformation. Stress
   changes in the range less than the
   preconsolidation stress produce elastic
   deformations of small magnitude. In fine-
   grained materials, stress increases beyond
   the preconsolidation stress produce much
   larger deformations that are principally
   inelastic (nonrecoverable)[2I].

stress, seepage. When water flows through
   a porous medium, force is transferred
   from the water to the medium by viscous
   friction. The force transferred to the
   medium is equal to the loss of hydraulic
   head.  This force, called seepage force, is
   exerted in the direction of fiow[21].

stress, shear. Stress directed parallel
   (tangential) to the surface element across
   which it acts.

strike. The direction or azimuth of a
   horizontal line in the plane of an inclined
   stratum, joint, cleavage plane or other
   planar feature within a rock mass.

strike valley. A valley following the strike
   of underlying strata[16].      .

structure. One of the larger features of a
   rock mass (e.g., bedding, foliation,
   jointing, cleavage, brecciation, etc.). Also
   the sum total of such features as
   contrasted with texture.  In a broader
   sense, it refers to the structural features of
   an area such as anticlines or synclines.

structural factor.  Features modifying or
   interrupting the  continuity of rock
   types[16].
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structural geology. That part of geology
  dealing with structures formed in
  rocks[16].

struga. (Slavic.) A corridor formed along a
  bedding plane in karst country^01.

stygobite. An aquatic troglobite[23].

stygophile.  An aquatic troglophile[23].

stygoxene. An aquatic trogloxene[23].

stylolite. An irregular suture-like boundary
  developed along some bedding planes in
  limestones, probably caused by
  dissolution under pressure and possibly
  related in some cases to subsequent
  inception of speleogenesis[9[.

subaqueous spring. See spring,
  subaqueous.

subaqueous karst. A karst terrane that is
  covered by a discrete body of water[17).
  See also drowned karst; subfluvial karst;
  submarine karst.

subartesian well.  An artesian well with
  insufficient head to raise water above the
  land surface116].

sub-conduit. Any void, whether of tectonic
  or dissolutional origin, that is smaller
  than the accepted defined size of a
  conduit.  Sub-conduits originate under
  inception conditions and enlarge during
  gestation, but many fail to achieve larger
  dimensions when drainage later becomes
  concentrated along preferred routes. In
  most cases, however, they will continue
  to function as part of the micro-fissure, or
  percolation, system within the rock mass.
  Sub-conduits are an essential part of a
  continuum of void sizes that extends
  between microscopic discontinuities and
  the largest tube passages191.

subcutaneous drain. Discrete percolation
  drains contained within the epikarst zone
  and leading to the transitions zone. See
  also epikarst zone; subcutaneous flow;
  subcutaneous zone; transition zone.

subcutaneous flow.  Lateral and vertical
  flow that occurs within the epikarst zone
  under saturated conditions. Lateral flow
  distances can exceed hundreds of meters
  and several meters per day while vertical
  within discrete percolation drains
  (subcutaneous drains) may allow flow
  rates in excess of several hundred meters
  per hour.  See also epikarst zone;
  subcutaneous drain; subcutaneous zone;
  transition zone.

subcutaneous zone.  Synonym for epikarst
  zone.

subfluvial karst. Karst topography
  developed beneath a river. See also
  subaqueous karst.

subjacent karst.  Karst landscape in non-
  carbonate rocks due to presence of
  karstified rocks beneath the surface
  formation[10]. Synonyms: (French.) Itarst
  sous-jacent; (German.) unterirdisches
  Karstphanomen; (Greek.) ypokimenon
  karst; (Russian.) pokritij karst; (Spanish.)
  karst subyacente; (Turkish.) gizli karst;
  (Yugoslavian.) pokriven kfs(kras).  See
  also interstratal karst.

subkutan karst.  See subsoil karst.
                                            184

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sublacustrine spring. See spring,
   sublacustrine.

sublimation. The direct conversion of
   water from its solid state to the vapor
   phase[16].

submarine karst. Karst topography
   developed below the tidal zone.  See also
   subaqueous karst.

submarine spring.  See spring, submarine.

subpermafrost karst.  Underground karst
   in areas of permafrost. Karstification is
   due to the solvent action of subpermafrost
   (or intrapermafrost) water[20]. Synonyms:
   (French.) karst sous-permafrost;
   (German.) Pseudokarst; (Greek.) karst
   ypomonimou paghetou; (Italian.)
   carsismo di subpermafrost; (Russian.)
   podmerzlonij karst, mezmerzlotnij karst;
   (Spanish.) karst de subpermafrost, karst
   de intrapermafrost; (Turkish.) don alam
   yeralti karsti.  See permafrost karst. See
   also intrapermafrost karst.

 subpermafrost water. Ground water below
   the permafrost[16].

 subsequent river.  1. A river flowing along
   the strike of a weak formation1161. 2. A
   tributary to a consequent river[16].

 subsidence. Lowering of the surface of the
   ground because of removal of support.
   Caused in karst areas by subterranean
   solution or collapse of caves[10].

 subsidence doline. A closed karst
   depression formed due to local
   subsidence of the surface rocks and/or
   soil into  cavities formed by widespread
  dissolution or local collapse of caves.
  The type of subsidence doline formed by
  downwashing of the soil cover is better
  described as a suffosion doline[9]. Also
  known as sinkhole.
      • t

subsidence/head-decline ratio. The ratio
  between land subsidence and hydraulic
  head decline in the coarse-grained beds of
  the compacting aquifer system[21].

subsoil karst. Karst covered by soil,
  usually residual soil[17]. Synonyms:
  (British.) soddy karst; (French.) karst vert,
  karst subcutane; (German.) bedeckter
  Karst, bodenbedeckter Karst, grukarst,
  subkutan karst; (Greek.) ypethaphikon
  karst; (Russian.) zadernovannyl karst;
  (Spanish.) karst subcutdneo; (Turkish.)
  toprakalft. karsti; (Yugoslavian.)
  pokriveni kfs(kras). See also covered
  karst.

subsurface divide. See underground
  divide.

subsurface flow. See subsurface runoff.

subsurface runoff, storm seepage,
   subsurface flow, subsurface storm flow.
   Runoff due to infiltrated precipitation
   moving laterally under the surface.

subsurface water.  All water that occurs
   below the land surface[22].

subterranean. Beneath the land surface[16].

subterranean cut-off. The diversion
   underground of a surface watercourse
   beneath a surface meander rieck, marked
   by a swallow hole on the upstream side
                                            185

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   and a spring on the downstream side[19].
   See also stream piracy.

subterranean river, subterranean stream.
   Underground stream of flowing water in
   caves and caverns, but not necessarily
   large[10]. See also underground stream.

suction.  See moisture tension.

suffosion. Undermining through removal of
   sediment by mechanical and corrosional
   action of underground water[20].
   Synonyms: (French.) soutirage karstique;
   (German.) Anzapfung; (Greek.)
   ypoghion thiavrosis; (Russian.)
   suffozija; (Spanish.) sufosion; (Turkish.)
   karstikyeraltisuyu kazimasv,
   (Yugoslavian.) sufozija.

suffosion doline. More accurate synonym
   for a type of subsidence doline, indicating
   formation by the suffosion, or
   downwashing, of the soil into an
   underlying fissure[9]. Also known as
   shakehole.

sulfate. A mineral compound characterized
   by the sulfate radical SO42~. Anhydrous
   sulfates, such as barite, BaSO4, have
   divalent cations linked to the sulfate
   radical; hydrous and basic sulfates, such
   as gypsum, CaSO4.2H2O, contain water
   molecules[1].

sulfate minerals. Minerals containing the
   SO42~ radical, formed by precipitation
   from water. The most common are the
   anhydrous and hydrated calcium sulfates,
   anhydrite (CaSO4) and gypsum
   (CaSO4.2H2O). Sulfates are deposited as
   a generally minor component  of most
   carbonate successions, but due to their
  high solubility they may not survive
  subsequent dissolution by ground water.
  Even if they survive subsequent
  dissolution by ground water. Even if they
  survive at depth, they tend to dissolve as
  they are raised nearer to the surface
  following uplift and erosion of
  overburden. Removal of sulfates by
  dissolution may contribute to the early
  establishment of secondary permeability
  in limestone sequences. Sulfate solutions
  have a limited corrosional effect upon
  calcium carbonate, but may also be
  oxidized to produce sulphuric ;acid, which
  is highly corrosive of limestone.

sulfate-reduction karst. Karst topography
  developed in the subsurface where
  solution of bedrock is chiefly a result of
  sulfate reduction by petroleum
  hydrocarbons aided by bacterial processes
  that oxidize hydrocarbons to yield carbon
  dioxide.  Little, if any of the water that
  dissolves the rock is meteoric[I7].

sulflde. A mineral compound characterized
  by the linkage of sulfur with a metal or
  semimetal, such as galena, PbS, or pyrite,
  FeS2[1].  See also gypsum and pyrite.

sulfide minerals.  Minerals that are
  composed of one or more metals
  combined with sulphur.  The most
  common is pyrite.  They are believed to
  be produced by the metabolic action of
  micro-organisms, and are found in many
  sedimentary rocks, usually in trace
  amounts.

sumidero.  (Spanish.) 1. A swallow hole. 2.
  In Latin America, any closed depression
  caused by solution[10].
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summation curve. A curve of cumulated
  values1161.                          -*i'

summit. The highest point of a
  physiographic feature[16].

sump. 1. In caves a sump is a section of
  flooded passage.  This may be a perched
  sump, probably quite short, within a
  vadose cave and created by a local reverse
  passage gradient. Alternatively it may be
  a major feature, where a cave passage
  descends below the regional water table
  into the phreas, as is common at the lower
  end of many cave systems.  Some short
  sumps can be dived without the use of
  breathing apparatus, but most are
  restricted to exploration by cave divers.
  Logistics are a barrier to endless sump
  penetrations, but some have now been
   explored for many kilometers in length,
   notable in Cocklebiddy Cave, Australia,
   the Nohoch Nah Chich and other great
   flooded systems in Mexico's  Yucatan,
   and behind Keld Head in Yorkshire[9]. 2.
   A pool of underground water or point on
   an underground stream that has a
   submerged extension, the nature of which
   has not been determined1101. 3. A place
   where the ceiling of a passage drops to
   and below water level in a cave, leaving
   no air space with the cave passage
   continuing underwater1131. 4. A water
   trap.

 sulfuric acid. An acid (H2SO4).
 sunken pan. An evaporation pan buried in
    the ground for equal elevation of the
    water surface with the ground surface1161.
superimposed valley. A valley established
  on .the;land surface with a pattern that is
  independent of the underlying rock
  structure.

supersaturated. Referring to water that has
  more limestone or other karst rock in
  solution than the maximum
  corresponding to normal conditions1^251.

supersaturation. A liquid that is over
  saturated with respect to whatever
  particles may be contained in the fluid.

suprapermafrost karst.  Surface karst in
  areas or permafrost.  Karstification is due
  to the solvent action of suprapermafrost
  water[20].  Synonyms: (French.) karst
  suprapermafrost; (German.)
  Pseudokarst; (Greek.) karst epi
   monimou paghetou;  (Italian.) carsismo
  superficial di permafrost; (Russian.)
   nadmerzlotnij karst; (Spanish.) karst de
   suprapermafrost; (Turkish.) don alan\
  yuzey karsti. See also permafrost karst.

 suprapermafrost water.  Ground water
   above permafrost161.

 surf karren. Surf karren form along marine
   limestone and dolomite coasts where the
   surf sprays water onto abrasion surfaces
   that lie slightly above normal sea level.
   They are a result of corrosion caused by
   the mixing of sea- and rainwater, but do
   not exist under the sea surface as seawater
   is not limestone-corrosive. Beyond the
   splashwater zone the karren are much less
   sharp[3].

 surfactant. A substance capable of
   reducing the surface tension of a liquid in
   which it is dissolved.  Used in air-based
                                            187

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  drilling fluids to produce foam, and
  during well development to disaggregate
  clays161. Surfactants are now being
  considered for the purpose of aquifer
  remediation by helping disperse
  immiscible contaminants.

surface detention. Sheet flow of water in
  overland flow before a channel is
  reached1161.

surface entry. An opening immediately at
  the land surface that permits infiltration to
  take place[16].

surface film. A monomolecular film of
  organic compounds forming on water or
  grain surfaces1161.

surface mapping.  The topographic and
  geodetic mapping of an area[16].

surface mine. Strip mine[16].

surface retention.  Water held on land
  surface1161.

surface runoff. That part of runoff
  traveling over the ground surface and
  through channels[16].

surface seepage. Surface discharge of
  ground water not important enough to
  form a rivulet[16].

surface spreading. A method of artificial
  recharge of water to an aquifer by
  spreading on a surface[16].

surface tension. The free specific surface
  energy occurring at the interface between
  a liquid and its own vapor phase[16].
surface water.  Water obtained from surface
  supplies1161.

survey. In caving, the measurement of
  directions and distances between survey
  points and of cave details from them, and
  the plotting of cave plans and sections
  from these measurements either
  graphically or after computation of
  coordinates^251.

susica. Yugoslavian term for intermittent
  stream or river in a karst terrane in which
  the water diverts and soaks gradually into
  the karst ground-water systemp01. See
  also intermittent river.

suspended load. Detrital matter being
  transported in suspension by a moving
  stream[16].

suspended matter.  Solid matter  small
  enough to be held in suspension by
  moving or stagnant water[I6].

suspended water.  See vadose water.

sustained yield. The rate at which water
  can be withdrawn from an aquifer without
  depleting the supply1161.

suunto clinometer®. A small, handheld
  pendulum clinometer commonly used in
  cave survey[25].

suunto compass®.  A small, handheld
  sighting compass commonly used in cave
  survey1251.                  .

swale. A marshy depression or depression
  in a ground moraine[16].
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swallet, swallow hole. (British.) A place
  where water disappears underground in^a
  limestone region.  A swallow hole
  generally implies water loss in a closed
  depression or blind valley, whereas a
  swallet may refer to water loss into
  alluvium at a streambed, even though
  there is no depression1101.  See also doline;
  ponor; sink; sinkhole; stream sink;
   sumidero.

swelling. The volume increase due to intake
   and absorption of water, especially
   clays[16].

swelling rate. The time rate of volume
   increase[I6].

swirlhole. A hole in rock in a streambed
   eroded by eddying water, with or without
   sand or pebble tools1251.

 synclinal valley. A valley following the
   axis of a syncline[16].

 syncline. Downfolded stratum[16].

 syngenetic karst.  1. Karst developed
   contemporaneously with the lithification
   of the formation, as in eolian calcarenite
   where lithification and karstification of
   dune sands may proceed
   simultaneously^101. 2. Karst landforms
   that developed upon young, porous
   carbonate rocks, such as aeolianites, as
   they underwent lithification191.
    Synonyms: (French.) karst syngenetique;
    (German.) Syngenetischer Karst;
    (Greek.) synegeticon karst; (Italian.)
    carsismo singenetico; (Spanish.) karst
    singenetico; (Turkish.) e^turumlu karst;
    (Yugoslavian.) singenetski kfs(kras).
syngenite. A cave mineral— :
  K2Ca(S04)2-H20[11].

synoptic network.  A network of first order
  stations permitting the regular observation
  of weather for all points at the same
  time!161.

synthetic unit hydrograph.  A unit
  hydrograph constructed by assuming the
  reaction of a drainage basin will be based
  on its physical characteristics1161.
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table mountain.  A flat topped mountain
tafoni. Roughly hemispherical hollows
   weathered in rock either at the surface or
   in caves[25].

tagging.  Affixing a metal tag bearing a cave
number near its entrance, normally by means
of rock drill and a small nail[25].

taihvater. The lower course of a river with
   respect to a given point of structure[I6].

talus cone.  A cone-like collection of
   disintegrated rock material originating
   from and adjacent to a steeper slope[16].

tape.  1 . In survey, a graduated tape of steel,
   plastic, wire-reinforced cloth, or
   fibreglass, used for measuring distance.
   2. Strips of woven synthetic fibre used for
   slings and waist bands[25].

taranakite.  A cave mineral —
   KA13(PO4)3(OH)-9H2O[1 1].

tarbuttite.  A cave mineral —
   Zn2(Pp4)(OH)[I1].

taylorite. A cave mineral —
tectokarst. Karst formed under the strong
  influence of tectonic disturbances.  The
  term is indefinite and its use is not
  generally recommended[20]. Synonyms:
  (French.) tectokarst; (German.)
  Tektonischer Karst; (Greek.) tektonikon
  karst; (Russian.) karst zon tektoniceskih
  razlomov; (Spanish.) tectokarst;
   (Turkish.) tektonik karst; (Yugoslavian.)
   tektokrs tektokras, tektokarst. •.

tectonic. Pertaining to structural features
   due to the deformation of the crust[16).

tectonic cave. A cave formed by some form
   of ground movement. The most common
   is due to landsliding in a jointed rock,
   leaving an open fissure cave parallel to
   the line of the hillside along the back of
   the slipped block. Tectonic caves can
   form in any rock, as they do not depend
   on dissolution. Well known examples are
   the windypit fissures of north-east
   Yorkshire, England some of which are
   hundreds of meters long and up to 60m
   deep[9].

tectonic valley.  A valley formed by tectonic
   forces[16].

temperature efficiency. An efficiency
   factor defined by Thornthwaite for
   different climates. See also
   Thornthwaite.

temperature log. A recording curve of
   ground-water temperature in a well[16].

temporary hardness.  See carbonate
   hardness.

tenorite. A cave mineral — CuO[I1].

tensiometer. A device used to measure the
   moisture tension in the unsatuf ated
  zone
      ,[22]
terminal moraine.  A glacial deposit
  accumulated in front of a glacier[16].
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terra rossa. 1. Reddish-brown soil
  mantling limestone bedrock; may be  y
  residual in some places1101.  2. Insoluble
  residuum of a reddish-brown color left
  behind when carbonate rocks weather
  under Mediterranean or allied climatical
  conditions1201. Synonyms: (French.) terra
  rossa; (German.) Kalksteinroterde;
  (Greek.) erythroghi; (Italian.) terra
  rossa; (Russian.) terra-rossa; (Spanish.)
  terra rossa; (Turkish.) kizil toprak,
  terrarosa; (Yugoslavian.) crvenica,
  jerina, jerovica.

terrace. A flat surface bounded by steplike
  steep slopes[16].

terraced flowstone. Shallow rimstone
  pools on outward-sloping walls[10].  See
  also rimstone barrage; rimstone barrier;
  rimstone dam; constructive waterfall.

terrain. An area with some specific
   characteristics. Reserved for surficial
   features only. Contrast with terrane.

terrane. An area with some specific
   characteristics1161. Includes both surface
   and subsurface features. Contrast  with
   terrain.

terrestrial. Living on land. Not to be
   confused with "epigean." Terrestrial cave
   animals include blind beetles, millipedes,
   spiders, and crickets[23].  See also aquatic.

tertiary porosity.  See porosity, tertiary.

test hole.  A hole to test the depth of ground
   water, water quality, or geological
   conditions^61.
texture.  The arrangement in space of the
  components of a rock body and of the
  boundaries between these components1161.

thalweg. A line of maximum depth of
  stream cross section[16].

Theis equation. The nonequilibrium
  equation of radial flow towards a well[16].
thenardite. A cave mineral —
thermal spring. See spring, thermal.

thermal stratification.  The stratification of
   water in reservoirs due to thermal-density
   differences1'61.

thermocline.  An intermediate layer in
   stratified water[16].

thermocouple. A temperature measuring
   device based on the proportionality
   between thermoelectric current and
   temperature difference between
   thermoj unctions1 ' 61 .

thermokarst. 1. A pitted periglacial or
   former periglacial surface in superficial
   deposits, produced by settling or caving
   of the ground after melting of ground
   ice[10].  2. A term applied to topographic
   depressions in karstic terranes resulting
   from the thawing of ice. See cryokarst.

thermokarst pit.  Steep-walled depression
   formed by thermokarst processes1101.

thickness. The perpendicular distance
   between bounding surfaces such as
   bedding or foliation planes of a rock.
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thief zone. The zone through which drilling
  fluid is lost into a formation through the
  borehole wall[I6].

Thiem equation. The equation that
  describes steady-state equilibrium radial
  flow into  a well[16].

thixotropy.  The property of a gel to
  become fluid under application of shear
  stresses"61.

thread. A natural hole through a rope, tape
  or wire can be passed to create an
  anchor^51.

threshold. That part of a cave system to
  which light penetrates in some degree[10].

threshold saturation.  Saturation below
  which no flow occurs1161.

through cave.  Cave through which a
  stream runs from entrance to exit or
  formerly did so[101. Synonym: (German).
  Ditrchgangshohle.

throughfall. A part of precipitation that
  reaches ground by falling through
  Vegetative cover[16].

throw. The vertical displacement of stratum
  along a fault plane[161.

thrust; thrust fault.  A generally gently
  dipping or subhorizontal fault plane
  where the relative movement has been
  essentially horizontal, with one rock
  sequence being pushed across and above
  another. Some cave  development in the
  Traligill area of north-west Scotland has
  been guided by thrust planes[9].
tidal river. A river strongly influenced and
  subject to tidal currents[16].

tidewell. See spring, ebb-and-flow.

tightest packing. An arrangement of
  particles allowing only minimum void
  space a unit cell of a sample1161.

till. Predominantly unsorted and unstratified
  drift, generally unconsolidated, deposited
  directly by and underneath a glacier
  without subsequent reworking by
  meltwater, and consisting of a \
  heterogeneous mixture of clay, silt, sand,
  gravel, and boulders ranging widely in
  size and shape[6].            !

tilted aquifer. A dipping aquifer[16].

time base.  The sum of storm duration time
  and concentration time in a
  hydrograph[161.

time-drawdown curve.  A plot of
  drawdown variation with time[161.

time lag. The time elapsed between the
  onset of a certain event and the reaction to
  this event[16].

time of concentration. The time required
  for surface runoff produced in the farthest
  part of a basin to reach a concentration
  point under consideration1161.

time of rise. The time between the first
  arrival of runoff and arrival of the peak
  fW161,

tinajita.  (Spanish.) See solution pan.
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tinticite. A cave mineral —
toadstone. Local term in the Peak District,
   England for lavas, tuffs and igneous
   intrusions within the local Carboniferous
   carbonate sequence.

topofil. A mechanical cave survey device
   that uses a roll of thread and a distance
   counter, a protractor to measure
   inclination and a compass to measure the
   bearing[25].

topographic divide. A crest line dividing
   one drainage basin from another'161. See
   also divide.

topographic map.  A map representing the
   land surface via the use of contour lines
   which are lines of equal elevation on the
   earth's surface.  Synonym: topo map.

topography. The physical features of a
   geographical area[16].

topsoil. The topmost portion of a soil
   profile[16].

torca. (Spanish.) Large closed depression,
   more or less circular; a doline[10].

torricellian chamber. A submerged air-
   filled chamber of a cave at a pressure
   below atmospheric pressure, sealed by
   water, having an air-water surface above
   that of adjacent free air-water surfacestl0].

tortuosity. The ratio of actual length of
   pore channel to over all length of sample.
   The sinuosity of actual flow path in a
   porous medium[16].
total dissolved solids, TDS. 1. The total
  concentration of dissolved constituents in
  solution, usually expressed in milligrams
  per liter[22].  2. The total concentration of
  dissolved material in water [as] ordinarily
  determined from the weight of the dry
  residue remaining after evaporation of the
  volatile portion of an aliquot of the water
  sample1221.

total hydraulic head. See head, total.

total pore space. The sum of
  interconnected and nonintercormected
  pore space[161.

total runoff. The sum of all components of
  runoff into a stream[16].

total soil-water potential.  The sum of the
  energy-related components of a soil-water
  system; i.e., the sum of the gravitational,
  matric, and osmotic components1221.

tourelle.  (French.) A little tower; applied to
  small flat-topped buttes of limestone in
  karst areas. Contrasted with pitons,
  which have pointed tops,  and with
  coupoles, which have rounded tops[101.

tower karst, towerkarst, turmkarst. 1. A
  spectacular variety of karst landscape
  dominated by steep or vertical sided
  limestone towers each 30—300m high.  By
  far the most extensive and best developed
  tower karst is the Guangxi. province of
  southern China. Towers originate as
  residual cones and are then steepened by
  water table undercutting from surround
   alluviated plains.  Tectonic uplift matched
  by karst erosion then increases tower
  heights, but if uplift exceeds surface
   lowering the towers are raised to hillside
                                             193

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  locations and the landscape is rejuvenated
  to form a new generation of dolines and
  cone karst. Many towers are riddled with
  relict caves at high levels, and with active
  caves through their bases[9]. 2. Karst
  topography characterized by isolated
  residual limestone hills displaying
  numerous shapes (e.g., cone shaped,
  steep-sided) separated by areas of allu-
  vium or other detrital sand; towers are
  generally forest-covered hills, and many
  have flat tops. They may form as isolated
  hills or in groups.  3. A type of karst
  topography, common in the tropics, in
  which the residual hills rise in steep-sided
  but fiat-topped mounds (resembling
  towers) from intervening depressions or
  dolinas (sinkholes)[20]. Synonyms:
  (French.) karst a tourelles,  karst a tours;
  (German.) Turmkarst, Kegelkarst;
  (Italian.) carsismo con forme residuali a
  torre;  (Spanish.) karst de torres;
  (Turkish.) kuleli karst. See also cone
  karst;  cupola karst; pinnacle karst;
  fengcong; fenglin.

trace. A short length of wire with fasteners
  used for attaching ladders and ropes to an
  anchor125'.

tracers.  Materials, such as chemicals, dyes,
  radioactive salts, and light insoluble
  solids introduced into underground waters
  to determine points of egress of the water
  and its velocity1101.

tracer-flow method. A method of
  determining flow velocities and directions
  by introducing tracers or indicators into
  ground water1163.

tracer gaging. Determining stream
  discharge by inserting a known quantity
  of dye and measuring its concentration
  after mixing[25].  Consists of either the
  tracer-dilution method or the tracer-
  velocity method (salt-velocity method).
  Synonym: dye gaging.

traction load. See bed load.    !

tranquil flow.  Open channel flow with
  Froude number smaller than uhity[16].

transgression.  The spreading of the sea
  over level areas1161.

transient. A pulse dampened oscillation or
  other temporary phenomena occurring in
  a system prior to reaching a steady-state
  condition1221. See flow, unsteady.

transition zone. 1. Portion of bedrock in
  the vadose zone that is between the
  epikarst zone and the phreatic .zone, is
  relatively waterless and unfractured, but
  is locally breached by discrete percolation
  points (vadose shafts.) 2. The zone in
  which the properties of two adjacent units
  change gradually (freshwater/saltwater).
   See also epikarst zone; subcutaneous
  drain; subcutaneous flow; subbutaneous
  zone; vadose caves; vadose shafts.

transit time; travel time. The travel time
   of a sonic impulse through a given length
   ofrock[I6].

transmission capacity.  The property of a
   porous medium to conduct fluid[16].

transmissibility coefficient. The use of the
   term transmissibility has been replaced by
   transmissivity[22].  See transmissivity.
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transmissivity. The rate at which water of
   the prevailing kinematic viscosity is  ;
   transmitted through a unit width of an
   aquifer under a unit hydraulic gradient161.
   Though spoken of as a property of the
   aquifer, it embodies the saturated
   thickness and the properties of the
   contained liquid as well. It is equal to an
   integration of the hydraulic conductivities
   across the saturated part of the aquifer
   perpendicular to the flow paths'221.

transpiration. The process by which water
   absorbed by plants, usually through the
   roots, is evaporated into the atmosphere
   from the plant surface'61.

transpiration depth.  The depth of water
   consumed annually by plants1161.

transpiration ratio.  The ratio of water
   weight transpired to weight of dry matter
   produced1161.

 transport.  Conveyance of solutes and
   particulates in flow systems. See also
   solute transport; particulate transport1221.

 transportational process. All processes
   contributing to the transport of eroded
   material1161.

 transverse permeability. See permeability,
   transverse.

 transverse wave. A wave generated by
    shearing displacement where wave
   motion is perpendicular to direction of
   propagation'161.

 trap. See siphon; sump; water trap.
traverse.  1. The commonest form of cave
   survey in which direction, distance and
   vertical angle between successive points
   are measured. 2. A way along ledges
   above the floor of a cave.  3. To move
   along such a way[251.

travertine.  1. Hard calcareous mineral
   deposited by flowing water, that is the
   same as the calcareous variety of sinter
   and comparable to the softer tufa. The
   term is normally used only for deposits
   formed outside caves,  where plants and
   algae cause the precipitation by extracting
   carbon dioxide from the water and give
   travertine its porous structure. Travertine
   forms most commonly on waterfalls that
   build up like gour dams.  Famous
   examples include those at Plitvice in
   Croatia, Dunn's River Falls in Jamaica,
   and, largest of all, Band-I-Amir in
   Afghanistan191.  2. Calcium carbonate,
   CaCO3, light in color and generally
   concretionary and compact, deposited
   from solution in ground and surface
   waters. Extremely porous or cellular
   varieties are known as calcareous tufa,
   calcareous sinter, or spring deposit.
   Compact banded varieties, capable of
   taking a polish, are called onyx marble or
   cave onyx[10]. 3. Generally compact
   calcium carbonate rock formed by
   precipitation of soluble bicarbonates
   when equilibrium is lost  due to changes in
   temperature and chemical characteristics.
   Soft, porous variety is called calcareous
   tufa[20]. Synonyms: (French.) travertin;
   (German.) Kalktuff, Sinter, Travertin;
   (Greek.) travertinis/asvestolithikos
   toffos; (Italian.) travertino; (Russian.)
   travertin; (Spanish.) travertino, toba;
    (Turkish.) traverten, suta§i;
    (Yugoslavian.) sedra, travertin, bigar,
    lehnjak. Related to sinter and tufa.
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 travertine terraces. Terraces and related
   forms covered or composed of carbonates
   precipitated from water. Such
   precipitation is usually from saturated
   bicarbonate waters (as from karst) when
   they enter a zone of turbulent flow[201.
   Synonyms: (French.) terrasse de
   travertin; (German.) Travertin-Terrace;
   (Greek,) anavathmos travertinou;
   (Italian.) spianata di travertine;
   (Spanish.) terrazas travertinicas;
   (Turkish.) suta^i tragalan;
   (Yugoslavian.) slapovi. See also
   constructive waterfall.

trellis. A geometrical arrangement of an
   interwoven pattem[16].

trellis drainage pattern. A arrangement of
   stream and tributaries in a rectangular
   fashion[1(il.

tributary.  A stream contributing its waters
   to another stream of higher order[16].

tributary river. A smaller stream entering
   and contributing to the flow of a larger
   river^.

tributary valley. A less important valley
   joining a larger valley1161.

tri-cam.  A metalic devise placed in holes or
   cracks for use as an anchor[25].  Compare
   chock

triple point.  A point at which the solid,
   liquid, and vapor phases are in
   equilibrium1161.

tripoly. A very fine grained silica sand[16].
 tritium. A short-lived isotope of hydrogen
   (A. = 12.43 y) that is directly incorporated
   into the water molecule as WjHO or
   ^TO [24].  Commonly used for tracing
   ground water and for age dating of ground
   water[I6]. See also radioisotope;
   radioactive tracer; tracers.

 Trittkarren. (German.) These are best
   described as heel-print karren because
   they resemble the imprint of a heel. They
   are nearly connected with subhorizontal,
   adjacent, flat plains and migrate upslope
   by cutting 'steps' through the process of
   retrogressive corrosion. The semi-
   circular form is preserved by the
   'horseshoe falls effect' which
   concentrates the main amount of water on
   the innermost part of the heel-print. At
   the upper rim the water gain speed.  The
   thickness of the film of water is indirectly
   proportional to the speed of the flow. A
   higher rate of flow results in a greater
   effectiveness of fresh precipitation added
   to the flow on the ground, but it also
   causes the diffusion of atmospheric CO2
   and more extensive corrosion.; Most
   Trittkarren originate at the rim of a grike
   lying below and have moved upward to
   the surface through retrogressive
   corrosion.  At the base of steep slopes
   where snow collects, nearly funnel-
   shaped Trittkarren appear and are of
   subnival origin. They are common in the
   Alps[3]. Synonym: heel-print karren.

trough. A depression usually on the land
   surface, but can be found to occur in
   ground water.

troglobite. 1. An animal living permanently
   underground in the dark zone of caves
   and only accidentally leaving it[10]. 2. A
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  creature that is fully adapted to life in
  total darkness and can only complete its^
  life cycle underground1131.  3. A creature;
  that lives permanently underground
  beyond the daylight zone of a cave.
  Many troglobitic species are adapted in
  some way to  living in a totally dark
  environment. Synonyms: (French.)
  troglobie; (German.) Troglobiont;
  (Greek.) troglothitis; (Italian.) troglobio;
  (Russian.) troglobiont; (Spanish.)
  troglobio; (Turkish.) troglobit, kor balik.

troglodyte. A human cave-dweller[10].
  Examples would be early 'cave man'.

troglomorphy. The physical characteristics
  of a troglobite or stygobite; e.g., reduced
  eyes and pigment, elongated appendages,
  well-developed tactile and olfactory
  organs, etc[23].

troglophile.  1. "Cave lover." An animal
  that can complete its life cycle in caves,
  but may also do so in suitable habitats
   outside caves[23].

troglophobe. An animal or person unable
   physically or psychologically to enter the
   dark zone of a cave or other underground
   area!101.

trogloxene.  1. "Cave visitor." An animal
   that habitually enters caves, but must
   return periodically to the surface for
   certain of its living requirements, usually
   food'231.

trophic levels. Feeding levels in a food
   chain, such  as producers, herbivores, and
   so on. Most food chains include a
   maximum of four or five trophic levels[23].
true velocity.  Ground-water flow velocity
  in porous interstice or cavernous
   opening[16].

True North. The direction of the
   geographical north pole at a place[25].

truncation. A horizontal or vertical clean
   cut through a topographic feature[15].

tsingi. Type of pinnacle karst found on
   limestone in Madagascar[9].

tube, lava.  See lava cave.

tubular passage; tube; tube passage. 1.
   Cave passage formed by approximately
   equal dissolution all round when full of
   flowing water within the phreas. Relict
   tubes, abandoned as the water table was
   lowered, are common in old caves, and
   may be partially filled by sediment,
   breakdown or stalagmite, or entrenched to
   form keyhole passages. Tube sizes range
   to over 15m in diameter, but the larger
   ones are rarely of uniform section.  Peak
   Cavern in Derbyshire is well known for
   its fine circular phreatic tubes.  Some of
   the trunk passages of Mammoth Cave,
   Kentucky, are spectacular tubes of
   elliptical section, formed by:dissolution
   rates that were higher along the bedding
   than across[9]. 2. These are nearly
   horizontal cave passages (tunnels) with
   round or elliptical cross sections and are
   either straight or winding. At Mammoth
   Cave they vary in size up to 30 feet high
   and nearly 100 feet wide. They are
   formed while completely filled with
   flowing water. Whereas they are typically
   wider than high as a result of dissolution
   along horizontal cracks and bedding-
   plane partings, they may also form as
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  high, narrow, straight fissures along
  major vertical or near vertical fractures[15].
  See also canyon passage; keyhole
  passage; passage; vertical shaft.

tubular spring. See spring, tubular.

tufa.  Soft, porous concretions of carbonate
  reprecipitated from saturated karst water,
  often around plants[22].  See also sinter;
  travertine.

tunnel. See natural tunnel.

turanite. A cave mineral —
  Cu5(V04)2(OH)4tul.

turbidity. A diminishing of light
  penetration through a water sample due to
  suspended and colloidal materials.

turbulence. An irregular motion of fluid
  particles in an inertia dominated flow
  regimen'161.

turbulent flow. 1. Type of flow that begins
  to develop in a dissolutional sub-conduit
  as its diameter increases to the point
  where differences between flow velocity
  at the bounding wall (slowed due to
  friction and adhesion) and the maximum
  velocity in the tube's center are sufficient
  to cause development of eddies within the
  flowing water1'1.  2. The flow  condition in
  which inertial forces predominate over
  viscous forces and in which head loss is
  not linearly related to velocity1221. It is
  typical of flow  in surface-water bodies
  and subsurface conduits in karst terranes
  provided that the conduits have a
  minimum diameter of approximately
  2-5mm although some research has
  suggested that 5-15 mm may be more
  appropriate. See also laminar flow;
  Reynolds Number; turbulent threshold.

turbulent threshold. The limiting value of
  sub-conduit size, below which water flow
  is essentially laminar and above which
  water flow includes a significant turbulent
  component. Sub-conduit diameters
  between 5mm and 15mm have been
  suggested as the minimum for turbulent
  flow, but the value depends upon a
  variety of factors, including the flow
  velocity; at low flow velocities laminar
  flow conditions may persist in tubes up to
  500mm in diameter[9].  See also laminar
  flow; Reynolds Number; turbulent flow.

turlough. (Irish.) 1. A karst depression that
  may be dry or flooded according to season
  or prevailing weather conditions; derived
  from the Irish term for 'dry lake'.
  Oscillations in the general ground-water
  level, including variations in response to
  local or more distant tidal effects are the
  probable mechanism for water level
  changes in the true turloughs.  Effects that
  appear similar can be produced by high
  surface runoff into a closed depression
  with only restricted capacity for the
  drainage to sink underground^1. 2. A
  depression in limestone or in glacial drift
  over limestone that is liable to flood
  either from excess surface runoff or from
  rising ground water.  From the Irish
  words tuar loch, meaning dry  lake[101.

Turmkarst.  (German.) See tower karst.

twilight zone. The area of a cave where
  light penetrating through the entrance is
  sufficient to permit human vision[23]. See
  also zonation.
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type curve.  A plot of the theoretical well
  function verses the lower limit of the <«
  integral in Theis' graphical solution
  method[16]. Numerous variations of
  Theis' original work have been developed
  for which type curves readily exist.

tyuyanrnnite.  A cave mineral —
  Ca(UO2)2(VO4)2-«H2O[11].
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                   U

unaltered rock.  Rock that has not
   experienced physical or chemical
   erosion1
         [16]
unconfined. A condition in which the
   upper surface of the zone of saturation
   forms a water table under atmospheric
   pressure[22].

unconfined aquifer. An aquifer where the
   water table is exposed to the atmosphere
   through openings in the overlying
   materials.

unconfined flow. Ground-water flow
   displaying a free surface1'61.

unconfined water.  Ground water vertically
   in direct contact with the atmosphere1161.

unconformity. A fossil land surface
   representing the absence of a sequence of
   sediments[16].

unconformity spring.  See spring,
   unconformity.

uncontaminated zone.  In electrical logging
   practice, the zone around a borehole that
   has not become contaminated by mud
   filtrate1161.

undercut karren. These are Rinnenkarren
   (solution grooves) that have been
   transformed by humus filling and by their
   side walls having been hollowed under by
   biogenic CO2[3].

 underflow spring.  See spring, underflow.
                              I
imderdrainage.  The drainage from under a
  hydrologic feature such as a river, barrier,
  lake, etc.

underfit stream.  A small stream that flows
  along a cave passage that was enlarged to
  its current size by an earlier, larger
  stream. Commonly underfit streams are
  found flowing under vadose conditions
  along the floors of drained phreatic tubes,
  long abandoned by the phreatic flow that
  enlarged them. Underfit streams may also
  occur if the major flow in a vadose
  streamway is captured to lower levels by
  the opening of a new shaft.  The main
  flow no longer uses the downstream
  passages, leaving any tributaries to
  amalgamate as an underfit stream191.

underflow. Deep phreatic flow within an
   aquifer, along flow lines that are largely
  unrelated to the more obvious flow at
  higher levels. Underflow drainage may
  be slower than that in shallower systems,
   and may travel towards more distant
   and/or unrelated springs[9].

underground divide. Subsurface
   watershed between two catchment areas
   in karst; often with incongruent with the
   surface topography of the area1201.
   Synonyms: (French.)  ligne departage des
   eaux souterraines, limit souterrainne;
   (German.) unterirdische Wafierscheide;
   (Greek.) ypoghios ythroketis; (Italian.)
   spartiacque sotterraneo; (Russian.)
   vodorazdelpodzemnih vod; (Spanish.)
   divisoria subterrdnea; (Turkish.) yeralti
   su boltimu; (Yugoslavian.) podzemna
   razvodnica, podzemna vododelnica. See
   also subsurface divide.
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underground river, underground stream.
  Water flowing in channels through caves,
  caverns, and larger galleries in karst
  terranes[20]. Synonyms: (French.) riviere
  souterraine; (German.) Hohlenflufi,
  unterirdischer Flu/3; (Greek.) ypoghios
  roe, potamos; (Italian.) fiume
  sotterraneo; (Russian.) podzemnaja
  reka; (Spanish.) rio subterrdneo;
  (Turkish.) yeralti nehri, deresi;
  (Yugoslavian.) podzemni tok, podzemna
  rijka, podzemna reka. See subterranean
  river.

underground waters. All subsurface
  waters[16]. Not to be confused with
  ground water which specifically refers to
  water within the phreatic zone.

uniaxial (unconfined) compression.
  Compression caused by the application of
  normal stress in a single direction.

uniaxial state of stress.  The state of stress
  in which two of the three principles
  stresses are zero.

uniform flow. Flow with constant velocity
  at all points and at all times[16].

uniformity coefficient.  A numerical
  expression of the variety in particle sizes
  in mixed natural soils, defined as the ratio
  of the sieve size on which 40% (by
  weight) of the material is retained to the
   sieve size on which 90% of the material is
  retained[6].

unit-hydrograph. A hypothetical discharge
  hydrograph for a given point resulting
   from unit rainfall which produces unit
   runoff1163.
unsaturated coefficient of permeability.
  The apparent coefficient of permeability
  in flow through an unsaturated
  medium[I6].

unsaturated flow. 1. The movement of
  water in a porous medium in which the
  pore spaces are not filled to capacity with
  water[22].  2. Two phase fiow;through
  pores only partially filled with water and
unsaturated zone. See vadose zone and
  zone of aeration.

unsteady flow. Flow with a finite local
  acceleration term and streamlines that
  vary with time[16].

unterirdische karst. See interstratal karst.

upconing.  Process by which saline water
  underlying freshwater in an aquifer rises
  upward into the freshwater zone as a
  result of pumping water from the
  freshwater zonet22].

uplift. 1. The hydrostatic force of water
  exerted on or underneath a structure
  tending to cause a displacement of the
  structure. 2. The relative upward
  movement of apart of the earth's crust[16].

upper confining bed.  An impermeable bed
  overlying an aquifer[16].

upside-down channel. See ceiling channel.

urkarst. See buried karst.    !

uvala. 1 . A multi-coned closed depression;
  now little-used term of Croat, Serb or
  Bulgarian origin.  The term was
                                            201

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introduced to describe features assumed
to be the second step in a 3-stage process
of polje development, in which dolines
were supposed to coalesce into uvalas.
This mechanism is no longer accepted
and the term uvala has fallen into
disuse191. 2. Large closed depression
formed by the coalescence of several
dolines which have enlarged towards each
other.  Typically, the floor is irregular,
being a combination of doline floors and
degraded slopes of the individual
hollows1191. 3. A Yugoslavian term for an
elongated closed depression in karst that
is commonly dry or with periodical small
sinking streams or inundations. They are
generally  a few hundred meters long and
may be considered as a small polje[201.
Synonyms: (American.) compound
doline; (French.) cuvala; (German.)
Uvala; (Greek.) ouvala; (Italian.)
awalamento carsico, uvala; (Russian.)
uvala; (Spanish.) uvala; (Turkish.)
koyak; kokurdan; (Yugoslavian.) draga.
See also canyon; karst valley; valley sink.
Related to polje.
                                          202

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                    V
vadose cave. 1. A cave that underwent most
   of its development above the water table.
   Within the vadose zone, drainage is free-
   flowing under gravity, and cave passages
   therefore have air above any water
   surface.  The gravitational control of
   vadose flow means that all vadose cave
   passages drain downslope, they exist in
   the upper part of a karst aquifer, and they
   ultimately drain into the phreatic zone or
   out to the surface.  Active stream caves,
   explorable by non-diving cavers, are by
   definition vadose (though they generally
   have phreatic origins).  Characteristics of
   vadose caves are uneroded ceilings
   (except for immature phreatic features
   pre-dating the vadose conditions) and
   continuous downhill gradients (unless
   interrupted by short perched sumps). The
   main passage forms are canyons, with
   meanders and potholes, broken by sub-
   cylindrical, spray-corroded shafts that
   may demonstrate waterfall retreat.  Some
   of the caves of Monte Canin, Italy, are
   spectacularly long and deep vadose
   systems'-91. 2. Older, higher cave passages
   found in the vadose zone; usually vadose
   caves have been abandoned by the ground
   water except in times of extreme aquifer
   recharge. Passages are usually appear as
   canyons and keyholes.

vadose flow. Water flowing in free-surface
   streams in caves1251.

vadose seepage. See percolation,
   percolation water.

vadose shaft. A vertical tube in the vadose
   zone that may be a few inches to several
   feet in diameter and may be a few feet
  deep to hundreds and over a thousand of
  feet deep. They commonly occur as
  complexes.  A drain hole is usually
  evident at their base. See also vertical
  shaft.

vadose water. 1. That part of the
  underground water in a karst limestone
  which circulates freely under gravity
  above the level of saturation - the vadose
  zone.  Caves formed by flowing water are
  said to be vadose caves[l9].  2. Water in the
  zone of aeration; water above the zone of
  saturation[10].

vadose zone.  1. The zone between the land
  surface and the water table[22]. 2. The
  zone between the land surface and the
  deepest water table which includes the
  capillary fringe.  Generally, water in this
  zone is under less than atmospheric
  pressure, and some of the voids may con-
  tain air or other gases at atmospheric
  pressure.  Beneath flooded areas or in
  perched water bodies the water pressure
  locally may be greater than
  atmospheric[22].  When discussing a karst
  setting, it is preferable to use the term,
  vadose zone, so  as to avoid confusion
  regarding chemical saturation. Synonym:
  unsaturated zone.  See also zone of
  aeration.

valley fill.  Unconsolidated debris
  accumulated on a valley bottom[16].

valley sink. (American.) An elongated
  closed depression or series of
  interconnecting  depressions ^forming a
  valley-like depression. Compare karst
  valley; uvala[10].

valley spring. See spring, valley.
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vanadinite. A cave mineral —
  Pbs(V04)3Cl[n].

vaporization. The process by which liquid
  or solid water changes into the gaseous
  state1161.

variable-temperature zone.  The area of a
  cave where air temperature fluctuates
  with the seasons. See also zonation.

variance. The square of the standard
  deviation1161.

variscite. A cave mineral —
  A1PO4-2H2O[11].

varve. The alternating of coarse and fine
  grained layers in glacial lake
  sediments[16).

vasque.  A large, shallow solution pan
  formed in the intertidal zone of warm seas
  by the action of brine and marine
  organisms1191.

vauclusian spring; vauclusian rising.  See
  spring, vauclusian.

vegetation cover.  The cover living
  vegetation on top of the upper soil
  horizon1161.

vein. A mineral filled fracture cutting
  through a host rock. The mineral filling
  may be derived from the host rock, as is
  the case with many calcite veins in
  limestone (e.g. at Marble Showers in
  Ogof Ffynnon Ddu) or derived from
  other, generally deeper, sources, such as
  the many veins containing lead and zinc
  ore minerals in the Derbyshire Peak
  District, England191.
velocity, average interstitial. The average
  rate of ground-water flow in interstices
  expressed as the product of hydraulic
  conductivity and hydraulic gradient
  divided by the effective porosity.
  Synonymous with average linear
  ground-water velocity or  effective
  velocity.

vermiculation. Pattern of thin,
  worm-shaped coatings of clay or silt on
  cave surfaces[25].

vertebrate.  An animal with a backbone.
  The group includes fishes, amphibians,
  reptiles, birds, and mammals. Some
  amphibians and fishes live permanently in
  caves. See also invertebrate.
vertical angle.  The angle in a vertical plane
   between a line of sight and the horizontal,
   positive above the horizontal and negative
   below[25].

vertical cave. A vertical passage within a
   cave system, formed along joints by
   which underground watercourses are
   transferred from a higher to a lower
   bedding plane[19].  They may bpcome
   transformed into vertical shafts by
   sufficiently uniform dissolution as to
   create a rounded vertical passage. See
   also fissure cave; vertical shaft.

vertical shaft.  These are formed by
   underground water dripping of flowing
   straight downward through the limestone
   along vertical cracks. Uniformly
   distributed dissolution of the rock results
   in a silo- or well-shaped passage so that
   most of them appear roughly circular in
   cross section when viewed straight up and
                                            204

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   down. They form above active tubular
   passages although they may intersect a-.
   limited number of passages along their
   length. At Mammoth Cave, they range in
   size from 30 feet across to 200 feet from
   top to bottom[15]. Synonym: dome-pit.
   See also canyon passage; fissure cave;
   keyhole passage; passage; tubular
   passage; vadose shaft; vertical cave.

vertical caver. A caver who enjoys and is
   competent doing vertical caving[13].  See
   also vertical caving.

vertical caving.  Caving that includes a lot
   of ascending and descending1133.  See also
   vertical caver.

very fine sand. Grain particles with
   diameters ranging from 0.05 to 0.1
vesicular. Containing small circular
   cavities[16].

victor tube. The single phreatic sub-conduit
   among the many that potentially exist on
   a given bedding plane (or fracture plane)
   that is the first to reach a diameter
   capable of establishing turbulent-flow
   conditions.  Following this breakthrough
   the victor tube tends to enlarge more
   rapidly than other branching or sub-
   parallel alternatives and eventually
   captures much of the drainage within its
   field of influence191.

virgin flow. Flow unaffected by artificial
   diversions, impoundments, or channels[16].

virgin passage.  A cave passage that has not
   previously been entered; a new
   disco very[13].
viscosity. 1. The resistance of liquid to
  flow[16].  2. The property of a real fluid
  creating shear forces between two fluid
  elements and giving rise to fluid
  friction[16]. Specifically, it is the ratio of
  the shear stress to the rate of shear
  strain[6].

void. See interstice.

void ratio. The ratio of (a) the volume of
  void space to (b) the volume, of solid
  particles in a given soil mass.t22J.

volatiles. Substances with relatively large
  vapor pressures. Many organic
  substances are almost insoluble in water
  so that they occur primarily in a gas phase
  in contact with water, even though their
  vapor pressure may be very small[22].

volumetric flowmeter.  Apparatus designed
  to measure a volume flow rate[16].

volumetric moisture content. The
  concentration  of water in soil by
  volume[I6].                 ;

vrulje.  (Yugoslavian.) See submarine
  spring.

vug. A small cavity in rock usually lined
  with crystals.  Adjective, vuggyt101.  See
  also geode.

vugular pore space. Void space due to
  solution cavities of small size[16].

vulcanokarst. An area comprised of tubular
  caves within lava flows and shows
  evidence of mechanical collapse of the
  roof into them. See also lava cave;
  pseudokarst.               ;
                                            205

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                   w

wading measurement. Discharge
  measurement during which a
  hydrographer takes readings while
  standing in a river[I6].

wall block.  A roughly cubical joint-con-
  trolled large block of limestone or dolo-
  mite, which has rotated outward from a
  cave walltloj. See also cave breakdown;
  wall slab.

wall karren. These are found on vertical
  walls as a result of water flowing down
  the walls without any area-wide
  moistening although area-wide sprinkling
  occasionally influences their
  development133. See also meandering
  karren; humus-water grooves.

wall pocket. See pocket.

wall slab. A thin but large block of rock,
   which has fallen outward from the wall of
   a cave in limestone in which the dip is
   nearly vertical[10]. See also cave
   breakdown.

wang. (Malaysian.) Polje[I01.

wash. A small ravine due to outwash by
   flow in desert regions[16].

wash load. The incoming load of
   suspended sediment passing through a
   river network without deposition[16].

waste load. The content of wastes by
   weight of volume transported by or
  , discharged into a river[16].
waste water. Water containing sewage and
  waste products1161.

water-balance. An instrument designed to
  measure evaporation by gravimetry[ll5].

water-bearing. Containing water[16].

water-borne disease. Disease spread by
  organic contaminants contained in the
  water supply1161.

water budget. The quantitative accounting
  of water volumes involved in the
  hydrologic cycle[16].

water catchment. The intake of water from
  an aquifer or a surface reservoir[16].

water conservation. All measures to
  reduce the quantitative of qualitative
  spoilage of water[16].

water content. The  amount of water lost
   from the soil after drying it to constant
  weight at 105°C, expressed either as the
  weight of water per unit weight of dry soil
   or as the volume of water per unit bulk
   volume of soil[22].  See moisture content.

water course. Any channel conveying
   water[16].

water equivalent. The depth of water
   resulting from the melting of snow[16].

water hammer.  An abnormally high
   pressure rise in a pipe when sudden
   changes in flow occur[16].

water-holding capacity. See specific
   retention.
                                            £06

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water invasion. The sudden invasion of
   water into a well or borehole[16].

water level. The level of free surface of a
   water body or water column[16].

water logged. Water saturated[16].

water logging. Water accumulation on top
   of soil where the water table and ground
   surface coincide1161.

water of constitution. Chemically bound
   water1161.

water of crystallization. Water embodied
   in crystal structure1161.

water of dehydration. Water freed from
   hydrous minerals by chemical changes[16].

water pot.  See kamenica, solution pan.

water quality. The physical, chemical, and
   biological characteristics of water[16].

water requirement. The quantity of water
   needed for crops regardless of the
   source[16].

water resources.  The total supply of
   surface, ground, and reclaimed water that
   can be used[16].

water stage. The height of the water
 water table. 1 . The top surface of a body of
   slowly moving ground water that fills the
   pore spaces within a rock mass. Above it
   lies the freely draining vadose zone, and
   below it lies the permanently saturated
   phreas. In uniform aquifers, such as
  sandstone, the water table is a smoothly
  contoured surface intersecting the ground
  at rivers and lakes, but in limestone it is
  more complex.  Individual cave conduits
  may be above or below the water table,
  and therefore either vadose or phreatic,
  and the water table cannot normally be
  related to them. The water table concept
  does, however, apply to the diffuse
  drainage of percolation water in the
  micro-fissure network of limestone, but
  its detailed structure may be complicated
  by the presence of conduits.  The water-
  table slope (hydraulic gradient) is low in
  limestone due to the high permeability,
  and the level is controlled by outlet
  springs or local geological features. High
  flows create steeper hydraulic gradients
  and hence rises in the water level away
  from the spring. In France's Grotte de la
  Luire, the water level in the cave (and
  therefore the local water table) fluctuates
  by 450m[9].  2. The upper surface of a
  zone of saturation except where that
  surface is formed by a confining unit[22].
  3. The upper surface of the zone of
  saturation on which the water pressure in
  the porous medium equals atmospheric
  pressure1221.  4. The upper boundary of an
  unconfined zone of saturation, along
  which the hydrostatic pressure is equal to
  the atmospheric pressure[10].  See also
  potentiometric surface.

water-table aquifer. See unconfined
  aquifer.

water-table cave. In theory the water table
  offers the prime environment for cave
  development as it provides the shortest
  route through the phreas and is potentially
  more active chemically due to the
  presence of the air/water interface.
                                            207

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  However, geological factors determine
  the details of cave inception and
  enlargement, and passages most
  commonly form just below the water
  table as a shallow phreatic variety of cave
  development. Development of this type
  is believed to be responsible for the
  'levels' of cave passage found in some
  areas, as in the flint Mammoth Cave
  System, Kentucky.  True water-table
  caves are rare except on a limited scale as
  extensions to cliff foot notches margined
  to tropical swamps. Also under these
  conditions, the water table may adjust
  down to the level of a mature phreatic
  cave and then modify  the passage with
  horizontal dissolution notches — as is
  common in the caves of Mulu and Niah,
  Sarawak191.

water-table divide. See divide.

water-table map.  A map showing the
  upper surface of the phreatic zone of a
  water-table aquifer by means of contour
  lines[1J.  See also phreatic zone;
  potentiometric-surface map; water-table
  aquifer.

water tracing. Underground drainage links
  through unexplored caves confirmed by
  labeling input water and identifying it at
  points downstream. The common
  labeling techniques involve the use of
  fluorescent dyes (fluorescein, rhodamine,
  leucophor, pyranine etc.), lycopodium
   spores, or chemicals such as common
   salt. Detection of dye downstream may
  be purely visual, but if the dye is used at a
   subvisible (environmentally acceptable)
   dilution, suitable detectors must be placed
   in all potential risings and collected for
   subsequent fiuorometric  examination
  (although water samples are more
  desirable and beneficial).  Lycopodium
  spores are usually collected in fine nets,
  along with other stream-borne sediment,
  and must then be identified under the
  microscope. If chemical tracers are used,
  regular water samples must be collected
  for subsequent analysis, or the resurgent
  waters must be monitored with suitable
  electronic detectors and recorders.
  Flowpaths can also be confirmed by
  transmission of artificial or natural flood
  pulses, which provide additional data on
  the nature of conduits, as a pulse is
  transmitted instantaneously through
  flooded passages. The longest successful
  water trace was from Beysehir Golu to the
  Manavgat springs, in Turkey, over a
  distance of 130km; 390kg of fluorescein
  was used and the dye reappeared after 366
  days[9].                     I
water trap, watertrap. A place where the
  roof of a chamber or passage of a cave
  dips under water but lifts again farther
  on[10].  Synonym: trap.

water works.  A plant where water is
  treated and prepared for municipal
  consumption1161.

water year. A 12 month period for
  streamflow computation[16].

waterlogged.  Water saturated.

waterlogging. Water accumulation on top
  of soil where the water table and ground
  surface coincide.
                                            208

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watershed.  1. A drainage basin[16]. 2. A
   divide separating one drainage basin from
   another[16].

waterway. An artificial or natural
   watercourse fit for navigation.

wave karren. Wavy karren surfaces that
   appear similar to corrugated tin. When
   denuded they are a disposition for the
   formation of Rinnenkarren[3]. See also
   covered karren; Rinnenkarren; root
   karren.

wayboard.  One of many thin beds of
   volcanic clay that occur at intervals
   within the Carboniferous carbonate
   succession of the Peak District, England;
   a term formerly used by lead miners (see
   toadstone). Wayboards have potential
   significance during speleogenesis when
   they may act as local aquicludes,
   inception horizons or providers of strong
   acid formed by oxidation of sulfide
   minerals191.

 weathering.  The process of disintegration
   and decomposition as a consequence of
   exposure to the atmosphere, to chemical
   action and to the action of frost, water and
   heat.

 wedge storage.  1. Water storage in the
    form of a wedge overlying a prism[16]. 2.
    storage in a flooded river segment[16].

 weir. A dam across a water course to
    control, raise, or measure water flow[161.

 weir coefficient. A coefficient used in
    transforming water depths into discharge
    volumes in weir measurements1161.
well.  1. A shaft or hole sunk into the earth
  to obtain water, oil, gas, or minerals1101. 2.
  A deep vertical rounded hole or shaft in
  the floor of a cave or at the bottom of a
  closed depression1101. 3. A bored, drilled
  or driven shaft, or a dug hole, whose
  depth is greater than the largest surface
  dimension1221.

well function.  An exponential integral as
  used in Theis'  nonequilibrium
   equation1161.                ;

well hydrograph. A graph of water level
   fluctuations  in a well1161.

well loss. Head loss caused by flow through
   a screen and inside a well[16].

well-sorted grains.  An assortment of grains
   having the same diameter[16].

well yield.  The volume of water discharged
   from a well  in gallons per  minute or cubic
   meters per day.

 wet line. That portion of line of submerged
   under water in stream measurements1161.'

 wet suit. A diving garment of, foam
   neoprene designed to insulate the diver
   from the cold  but which allows a thin film
   of water to penetrate between the suit and
   the body1251.

 wetland. A general term used for a group of
   wet habitats, in common use by
    specialists in wildlife management. It
    includes areas that  are permanently wet
    and/or intermittently water-covered,
    especially coastal marshes, 'tidal swamps
    and flats, and associated pools, sloughs,
    and bayoustl].
                                              209

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wettability. The property of a solid
   substance to be wetted by a liquid such as
   water1165.

wetted area. The cross sectional area of
   that portion of a channel that is filled with
   water1161.

wetted perimeter. The perimeter over
   which flowing water is in actual contact
   with the channel walls and bottom[16].

wetting period. The period of contact
   between a liquid and a solid surface
   during which wetting occurs[16].

whaletail.  A descender consisting of an
   aluminium block with slots, knobs and a
   safety gate1251.

whitlockite. A cave mineral —
   Cap(Mg,Fe)H(P04)7[11].

width of contribution. The width of the
   contributing region between the ground-
   water divide from which water enters a
   well.  This usually occurs with an
   inclined piezometric surface1161.

wilt, to.  The shrinking of cell walls due to
   loss in turgor as a result of water
   deficiency in the plant[16].

wilting coefficient, wilting point. The soil
   moisture content at which plants wilt[16].

wind factor.  The factor containing a
   monthly mean wind velocity in
   evaporation1161.

wind field. The air velocity field above
   ground due to wind action[16].
window.  1. hi speleology, a natural opening
   above the floor of a passage or a room,
   giving access to an adjoining cavity or to
   the surface; larger and less symmetrical
   than a porthole. 2. The opening under the
   arch of a small natural bridge[101. See
   karst window.

windypit.  Open fissure, widened by
   landslip, common in valley side situations
   where limestone overlies weaker rocks
   such as clays or shales.  The term is
   commonly used to describe gulls and
   tectonic caves in the Jurassic limestones
   of north-east Yorkshire, England[9].

withdraw, to. To draw water from an
   aquifer or reservoir[16].

workover. The reworking of a well that has
   declined in yield[16].
                                             210

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yield.  The quantity of water discharged
   from an aquifer[16] (e.g spring or well.)
   See also well yield.
                                                211

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 zadernovannyi karst. (Russian.) See
   subsoil karst.

 zakrytyi karst, skrytyi karst. (Russian.)
   See closed karst.

 zanjon.  (Spanish.) In Puerto Rico, solution
   trench in limestone. Zanjones range from
   a few centimeters to about 8 meters in
   width and from about 1 to 4 meters in
   depth. Apparently they form by the
   widening and deepening of joints by
   solution1'01. See also bogaz; corridor;
   struga.

 zero adjustment.  The adjustment of a scale
   or a measuring circuit to an original point
   ofdeparture[16].  .

 zonal soil profile. The normal horizontal
   distribution of soil zone[I6].

 zonation. The organization of a habitat into
   a more or less orderly series of distinctive
   plant and animal associations as a result
   of variations in environmental conditions.
   Zones in a cave are the twilight zone, the
   variable-temperature zone, and the
   constant-temperature zone[23].

zone of accumulation. The second horizon
   of a soil profile (B), usually the zone of
   clay accumulation subjacent to zone
   (A)"6'.

zone of aeration. The zone in permeable
   soil or rock that is above the zone
   saturated with water; the zone of vadose
   water1101. See also vadose zone.
zone of investigation.  The zone over which
   a given measuring device is able to obtain
   information116].

zone of leaching. The top horizon of a soil
   profile (A) that is most intensely
   weathered[16].

zone of saturation. The zone in permeable
   soil or rock that is saturated with water;
   the phreatic zone[10]. See also phreatic
   zone.

zones of karstification. Cvijic (1926,1960)
   distinguishes three zones of karstification:
   (1) dry zone in the upper part of the karst
   with caves almost completely dry; (2)
   transition zone where water flows
   downstream almost permanently; and (3)
   deep zone with slow downstream flow
   and local siphons[20]. Synonyms:
   (French.) zones de karstification;
   (German.) Zone der Verkarstung;
   (Greek.) zoni karstikopiiseos; (Italian.)
   zone idrogeologiche; (Spanish.) zona de
   karstificacion; (Turkish.) karstla^ma
   &wsagi; (Yugoslavian.) zone
   karstifikacije.

Zwischenhohle. (German.) Cave in which
   a river passage, or former river passage, is
   entered from above or laterally and which
   can be followed upstream and
   downstream some distance but not to
   daylight[10].
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            REFERENCES
1. Bates, R. L. and J. A. Jackson. 1980.
  Glossary of Geology. American
  Geological Institute. Falls Church, Va.
  751 pp.

2. Bear, J. 1979. Hydraulics of Groundwater.
  McGraw-Hill Inc. New York, NY. 569
  pp.

3. Bogli, A. 1980. Karst Hydrology and
  Physical Speleology. Springer-Verlag.
  Berlin, West Germany. 284 pp.

4. Daoxian, Y. 1985. New Observations on
  Tower Karst. Paper presented at the 1st
  International Conference on
  Geomorphologv (Manchester, England).
   14pp.

 5. Dreybrodt, W. 1988. Processes in Karst
   Systems: Physics. Chemistry, and
   Geology. Springer-Verlag. New York,
   N.Y. 288 pp.

 6. Driscoll, F. G. 1986. Groundwater and
   Wells. Johnson Division. St. Paul, Minn.
   1089 pp.

 7. Ford, D. C.  and P. W. Williams. 1989.
   Karst Geomorphologv and Hydrology.
   Unwin Hyman Inc. Lakeland,  Fla. 601 pp.

 8. Jennings, J. N. 1985. Karst
   Geomorphologv. Basil Blackwell Inc.
   New York, N.Y. 293 pp.

 9. Lowe, D. and T. Waltham. 1995. A
   Dictionary of Karst and Caves: A Brief
   Guide to the Terminology and Concepts
   of Cave and Karst Science. Cave Studies
  Series Number 6. British Cave Research
  Association. London, Britain.; 41 pp.
    *    7               '     .
10. Monroe, W. H. (Compiler). 1970. A
  Glossary of Karst Terminology.
  Geological Survey Water-Supply Paper
  1899-K. U.S. Geological Survey. U.S.
  Government Printing Office. Washington,
  D.C. 26 pp.

11. Moore, G. W. and G. N. Sullivan. 1978.
  Speleology: The Study of Caves. Cave
  Books. 2nd Edition. St. Louis, Missouri.
  150pp.

12. Mylroie, J. E. 1984. Hydrologic
  classification of caves and karst.
  Groundwater as a Geomorphic Agent. R.
  G. LaFleur, Editor. Allen & Unwin. Inc.
  Boston, Mass. pp. 157-172.

13. NSS. 1982. Glossary of caving terms
  used in this manual. Caving Basics. J.
  Hassemer, Editor. National Speleological
   Society. Huntsville, Ala. pp. 124-125.

14. Palmer, A. N.  1972. Dynamics of a
   sinking stream system: Onesquethaw
   Cave, New York. National Speleological
   Society Bulletin. 34- PP- 89-110.

 15. Palmer, A. N. 1981. A Geological Guide
   to Mammoth Cave National Park.
   Zephyras Press. Teaneck, NJ. 196pp.

 16. Pfannkuch, H. O. 1971. Elsevier's
   Dictionary of Hvdrogeology. American
   Elsevier Publishing Company. Inc. New
   York, N.Y. 168 pp.

 17. Quinlan, J. F. 1978. Types of Karst with
   Emphasis on Cover Beds in their
   Classification and Development.
                                           213

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   Unpublished Ph.D. Dissertation. The
   University of Texas at Austin. 323 pp.

18. Quinlan, J. F., P. L. Smart, G. M.
   Schindel, E. C. Alexander, A. J. Edwards,
   and A. Richard Smith. 1991.
   Recommended administrative/regulatory
   definition of karst aquifer, principles for
   classification of carbonate aquifers,
   practical evaluation of vulnerability of
   karst aquifers, and determination of
   optimum sampling frequency at springs.
   Hydrology. Ecology. Monitoring,  and
   Management of Ground Water in Karst
   Terranes Conference (3rd. Nashville.
   Term. 1991). J. F. Quinlan and A.
   Stanley, Editors. National Ground Water
   Association. Dublin, Ohio. pp. 573-635.

19. Sweeting, M. M. 1973. Karst
   Landforms. Selected Glossary. Compiled
   by K. Addison. Columbia University
   Press. New York, N.Y. 362 pp.

20. UNESCO. 1972. Glossary and
   Multilingual Equivalents of Karst Terms.
   United Nations Educational. Scientific.
   and Cultural Organization.  Paris, France.
   72pp.

21. UNESCO. 1984. Guidebook to Studies
   of Land Subsidence due to  Ground-Water
   withdrawal. Prepared for the International
   Hydrological Programme. Working
   Group 8.4. J. F. Poland, Editor. United
   Nations Education. Scientific and
   Cultural Organization. Paris, France. 305
   pp. (plus appendices).

22. USGS. (date ?). Federal Glossary of
   Selected Terms: Subsurface-Water Flow
   and Solute Transport. Prepared by the
   Subsurface-Water Glossary Working
   Group. Ground-Water Subcommittee.
   Interagency Advisory Committee on
   Water Data. Dept. of the Interior. U.S.
   Geological Survey. Office of Water Data
   Coordination. 38 pp.

23. William R. Elliott, Ph.D. of the Natural
   History Division of the Missouri
   Department of Conservation. The list of
   definitions were obtained directly from
   the Biospeleology web site:

   www.utexas.edu/depts/tnhc/. www/biospel
   eology

   which is based on The Life of the Cave by
   Charles E. Mohr and Thornas L. Poulson
   (1966, McGraw-Hill) with additions from
   Dr. Elliott.

24. Clark, I. and P. Fritz. 1997. :
   Environmental Isotopes in Hydrology.
   Lewis Publishers, Boca Raton, Fla. p.
   174.

25. Australian Speleological Federation.
   1996. Cave and Karst Terminology. The
   list of definitions were obtained directly
   from the Western Australia Speleology
   web site:

   http://wasg.iinet.net.au/terminol.html

   which contains a listing of terminology
   commonly used in Australia.
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