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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That Rinnenkarren is (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 damper [3].?

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Chemistry and Karst, White, William B.
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Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
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Your search for sinkholes (Keyword) returned 270 results for the whole karstbase:
Showing 256 to 270 of 270
EVAPORITE KARST IN THE PERMIAN BASIN REGION OF WEST TEXAS AND SOUTHEASTERN NEW MEXICO: THE HUMAN IMPACT , 2013, Land, Lewis

A significant minority of sinkholes in the greater Permian Basin region of west Texas and southeastern New Mexico are of human origin. These anthropogenic sinkholes are often associated with historic oil field activity, or with solution mining of Permian salt beds in the shallow subsurface. The well-known Wink Sinks in Winkler Co., Texas formed in 1980 and 2002 within the giant Hendrick oil field. The Wink Sinks were probably the result of subsurface dissolution of salt caused by fresh water leakage in improperly cased abandoned oil wells. In 2008 two catastrophic sinkhole events occurred a few months apart in northern Eddy Co., New Mexico, and a third formed a few months later in 2009 near Denver City, Texas. All three sinkholes were the result of solution mining operations for brine production from Upper Permian salt beds. The Eddy Co. sinkholes formed within the giant Empire oil and gas field, several kilometers from populated areas. In the aftermath of these events, another brine well operation was identified within the city limits of Carlsbad, New Mexico as having a similar geologic setting and pumping history. That well has been abandoned and geotechnical monitoring of the site has been continuous since 2008. Although there is no indication of imminent collapse, geophysical surveys have identified a substantial void in Permian salt beds beneath the brine well extending north and south beneath residential areas, a major highway intersection, a railroad, and an irrigation canal


Fault — Dissolution front relations and the Dead Sea sinkhole problem, 2013, Ezersky Michael, Frumkin Amos

There are two conflicting models of sinkhole development along the Dead Sea (DS). The first one considers structural control on sinkholes, constraining them to tectonic lineaments. This hypothesis is based on seismic reflection studies suggesting that sinkholes are the surface manifestations of active neotectonic faults that may serve as conduits for under-saturated groundwater, enabling its access across aquiclude layers. Another hypothesis, based on results of multidisciplinary geophysical studies, considers the salt edge dissolution front as themajor site of sinkhole formation. This hypothesis associates sinkholes with karstification of the salt edge by deep and shallow undersaturated groundwater. Our recent seismic reflection and surface wave studies suggest that salt formed along the active neotectonic faults. Sinkholes form in a narrow strip (60–100 m wide) along a paleo-shoreline constrained by faults and alluvial fans which determined the edge of the salt layer. This scenario reconciles the two major competing frameworks for sinkhole formation.


Karst Memories Above and Beneath the See: Marseilles and Continental Shelf During the Cosquer Cave Occupation, 2014, Collinagirard, Jacques

In the south of France, the Cosquer Cave with its famous prehistoric paintings is located in a karstic area located between Marseilles and Cassis. This emerged and submerged karst is typical of karstic coasts submerged after the Late-Glacial Maximum. Ail the forms observed in the hinterland can be observed directly by scuba divers and indirectly on bathymetrie charts: lapiaz, karstic archs, sinkholes, uvala and polje. The emerged and submerged landscapes are mainly the heritage of specifie lithological conditions (Urgonian limestones) and tectonic conditions (vertical faulting network leading to coastal eollapse in theMediterranean Sea). üther elements of this submerged Iandscape are given by the traces of the last sea level rise (palaeo-shorelines and erosion platforms and notehes). AIl the area between Marseilles and La Ciotat is now established as the Calanques National Park, inc1uding the Cosquer Cave with its upper Palaeolithic rock art paintings, which adds an international archaeological interest to this exceptional natural area.


ISOTOPIC STUDIES OF BYPRODUCTS OF HYPOGENE SPELEOGENESIS AND THEIR CONTRIBUTION TO THE GEOLOGIC EVOLUTION OF THE WESTERN UNITED STATES, 2014, Polyak V. J. , Asmerom Y. , Hill C. A. , Palmer A. N. , Provencio P. P. , Palmer M. V. , Mcintosh W. C. , Decker D. D. , Onac B. P.

Hypogene speleogenesis in the western United States is associated with a deep source of water and gases that rise and mix with shallow aquifer water. Caves are formed below the surface without surface expressions (ie, sinkholes, sinking streams), and byproducts of speleogenesis are precipitated during the late phase of hypogene speleogenesis. These byproducts provide geochemical and geochronological evidence of a region’s geologic history and include gypsum rinds and blocks, elemental sulfur, halloysite-10Å, alunite, natroalunite, and other sulfur-related minerals. The following speleogenetic and speleothemic features are common: alteration rinds, crusts, mammillaries, folia, rafts, and cave spar. The types of hypogene speleogenesis vary and many can be expressed in space and time in relation to paleo-water tables. We identify two general types: (1) H2S-H2SO4-dominated speleogenesis that takes place predominantly near a paleo-water table (a few meters above and below), and (2) CO2-dominated speleogenesis that mostly takes place 10s to 100s of meters below a paleo-water table, with latest-stage imprints within meters of the water table.
The Kane caves in Wyoming, and the Guadalupe Mountains caves in New Mexico and West Texas, are examples of H2S-H2SO4-dominated speleogenesis (also known as sulfuric acid speleogenesis, SAS), where deposits of H2S- and H2SO4-origin are the obvious fingerprints. The Grand Canyon caves in Arizona and Glenwood Caverns in Colorado are examples of CO2-dominated systems, where H2SO4 likely played a smaller role (Onac et al., 2007). Deeper-seated geode-like caves, like the spar caves in the Delaware Basin area, are probably CO2-dominated, and have formed at greater depths (~0.5 ± 0.3 km) below paleo-water tables. Caves in the Black Hills, South Dakota are composite and complex and show evidence for multiple phases of hypogene speleogenesis. In areas such as the Grand Canyon region, these paleo-water tables, when they existed in thick carbonate rock stratigraphy and especially at the top of the thick carbonate rock strata, were likely regionally relatively flat in the larger intact tectonic blocks.
Geochemical studies of these deposits are providing information about the timing of speleogenesis through U-Th, U-Pb, and Ar-dating. In addition, tracer data from isotopes of C, O, S, Sr, and U are indicators of the sources of water and gases involved in speleogenesis. From these studies, novel canyon incision and landscape evolution interpretations are appearing in the literature. Beyond this, the study of these byproduct materials seems to show evidence that the deeply sourced water and gases involved in hypogene speleogenesis in the western United States are generated during tectonic and volcanic activity, and may be related to mantle processes associated with formation of the Rocky Mountains, Colorado Plateau, Basin and Range province, and Rio Grande Rift.


Hydrological role of karst in the Chalk aquifer of Upper Normandy, France, 2014, Janyani S. El, Dupont J. P. , Massei N. , Slimani S. , Dörfliger N.

The role of karst on large-scale groundwater flow is defined for the Chalk aquifer of Upper Normandy (western Paris Basin), France. In the regional context, chalk plateaus occupy the greater part of watersheds and are the main sites of groundwater recharge. Previous studies focused on karstic output systems in the valleys and less on water-level variations in the recharge zones upstream. This study assesses the relevant hydrogeological processes using time-series data (boreholes and springs) recorded along a down-gradient hydrologeological cross-section in two selected watersheds. These hydrological data are interpreted in the framework of previous descriptions of the morphological organization of the study area’s karst network. The results highlight the hydrological role of (1) the input karst (vertical conduits) which drains recharging water, (2) the output karst (sub-horizontal conduits widely developed in the vicinity of valleys in the surface watersheds) which drains the output flows, and (3) the connections between these two (input and output) networks, which control the upstream water levels and allow quick transfer to springs, particularly after strong rainfall events. A conceptual model of the hydrological functioning of this covered karst aquifer is established, which should serve for the structuring and parameterization of a numerical model


Sagging and collapse sinkholes over hypogenic hydrothermal karst in а carbonate terrain, 2014, Frumkin A. , Zaidner Y. , Na'aman I. , Tsatskin A. , Porat N. , Vulfson L.

We show that clusters of karst sinkholes can occur on carbonate hypogene karst terrains. Unlike common doline karst of dissolution origin, the studied sinkholes form mainly by sagging and collapse. Thermal survey, OSL dating and morphologic analysis during quarrying and excavations are applied to study the sinkholes at the Ayyalon karst, Israel. The thermal survey shows the spatial pattern of rising warm water plumes, whose temperature is > 2 °C warmer than the surrounding aquifer water. These plumes dissolve the limestone, creating large voids and maze caves. Mass wasting forms surface sinkholes mainly by sagging and collapse. Both types of deformation often occur within the same depression. Lack of hydrologic connection between the surface and underground voids constrain drainage and promote rapid accumulation of colluvium, dust and pedogenic clays. These have filled the sinkholes up to their rim before the late Holocene. OSL dating constrains the rate of sediment accumulation within the sinkholes. The average filling rate (thickness divided by elapsed time) is ~ 47 mm ka− 1 for the last 53 ± 4 ka in Sinkhole 1, while in Sinkhole 2 (“Nesher Ramla karst depression”), the rate is ~ 61 mm ka− 1 from ~ 200 to 78 ka, and ~ 173 mm ka− 1 since ~ 78 ka. Between ~ 170 and 78 ka, Sinkhole 2 was intensively used by Middle Paleolithic hominins. The studied sinkholes may be considered as a type locality for hypogene sinkhole terrain on carbonate rocks.


Sinkholes, pit craters, and small calderas: Analog models of depletion-induced collapse analyzed by computed X-ray microtomography, 2014, Poppe S. , Holohan E. P. , Pauwels E. , Cnudde V. , Kervyn M.

Volumetric depletion of a subsurface body commonly results in the collapse of overburden and the formation of enclosed topographic depressions. Such depressions are termed sinkholes in karst terrains and pit craters or collapse calderas in volcanic terrains. This paper reports the first use of computed X-ray microtomography (?CT) to image analog models of small-scale (~< 2 km diameter), high-cohesion, overburden collapse induced by depletion of a near-cylindrical (“stock-like”) body. Time-lapse radiography enabled quantitative monitoring of the evolution of collapse structure, velocity, and volume. Moreover, ?CT scanning enabled non-destructive visualization of the final collapse volumes and fault geometries in three dimensions. The results illustrate two end-member scenarios: (1) near-continuous collapse into the depleting body; and (2) near-instantaneous collapse into a subsurface cavity formed above the depleting body. Even within near-continuously collapsing columns, subsidence rates vary spatially and temporally, with incremental accelerations. The highest subsidence rates occur before and immediately after a surface depression is formed. In both scenarios, the collapsing overburden column undergoes a marked volumetric expansion, such that the volume of subsurface depletion substantially exceeds that of the resulting topographic depression. In the karst context, this effect is termed “bulking”, and our results indicate that it may occur not only at the onset of collapse but also during progressive subsidence. In the volcanic context, bulking of magma reservoir overburden rock may at least partially explain why the volume of magma erupted commonly exceeds that of the surface depression.


A review on natural and human-induced hazards and impacts in karst, 2014, Gutiérrez Francisco, Parise Mario, De Waele Jo, Jourde Hervé

Karst environments are characterized by distinctive landforms related to dissolution and a dominant subsurface drainage. The direct connection between the surface and the underlying high permeability aquifers makes karst aquifers extremely vulnerable to pollution. A high percentage of the world population depends on these water resources. Moreover, karst terrains, frequently underlain by cavernous carbonate and/or evaporite rocks, may be affected by severe ground instability problems. Impacts and hazards associatedwith karst are rapidly increasing as development expands upon these areas without proper planning taking into account the peculiarities of these environments. This has led to an escalation of karst-related environmental and engineering problems such as sinkholes, floods involving highly transmissive aquifers, and landslides developed on rocks weakened by karstification. The environmental fragility of karst settings, togetherwith their endemic hazardous processes, have received an increasing attention from the scientific community in the last decades. Concurrently, the interest of planners and decision-makers on a safe and sustainable management of karst lands is also growing. This work reviews the main natural and human-induced hazards characteristic of karst environments, with specific focus on sinkholes, floods and slope movements, and summarizes the main outcomes reached by karst scientists regarding the assessment of environmental impacts and their mitigation.


Incipient vertical traction carpets within collapsed sinkhole fills, 2014,

Small vertically oriented traction carpets are reported from the collapsed sandy fills of 100 m deep Devonian limestone sinkholes underlying the Lower Cretaceous Athabasca oil sands deposit in north-eastern Alberta, Western Canada. Dissolution of 100 m of underlying halite salt beds caused cataclysmic collapse of the sinkhole floors and water saturated sinkhole sand fills to descend very rapidly. Turbulent currents flushed upper sinkhole fills of friable sandstone blocks and disaggregated sand and quartz pebble for tens of metres. Laminar deposits with inverse grading accumulated as many as six to eight curvilinear entrained pebble streaks, 10 to 30 cm long, vertically impinged against the sides of descending collapse blocks. These deposits were initiated as vertically oriented early stage traction carpets that interlocked fine sand grains and inversely graded overlying pebbles entrained below the dilute overlying turbulent flows. Vortexes that flushed these sinkhole fills and induced these depositional processes may have lasted only seconds before the very rapid descents abruptly halted. Some of the fabrics were suspended vertically in-place and preserved from unlocking and obliteration. These small fabrics provide insight into the instability and ephemeral character of the transition from strong gravity-driven grain falls to very early stages of traction carpet formation. These short-lived deposits of very thin sand layers resulted from sufficient incipient frictional freezing that grain interlocking overcame, however briefly, the strong gravity drives of the vertical falls that would have otherwise dispersed grains and obliterated any organized fabric patterns. Tenuous frictionally locked grains were also suspended at the centres of hyperbolic grain fall flows that briefly developed between turbulent flow eddies, some of which were fortuitously preserved. Some of these suspended grain locking zones passed downward onto the relatively more stable surfaces of the rapidly descending block surfaces. The morphogenesis of these early stage traction carpets differ from more fully developed deposits elsewhere because of their short-lived transport, dynamic instability and vertical orientation.


Deep speleological salt contamination in Mediterranean karst aquifers: perspectives for water supply, 2015,

On the Mediterranean coast, submarine karst springs are common. Most of them are brackish and various unsuccessful attempts in France, Greece, and Italy indicate that it is impossible to diminish the salinity at the spring. Based on studies on the shores of south-eastern France and in Kefalonia (Greece), we propose a working model that explains the mechanism of salt contamination. During the Messinian Deep Stage (-5.9 to 5.3 Ma), a substantial sea-level lowering in the Mediterranean allowed the existence of cave networks extending several hundreds of meters below the present sea level. Seawater is now sucked into the system through these caves. This mechanism is supported by a study of the Port Miou underground river (Cassis, France). In the Port Miou cave system, which extends to 250 m below sea level, titanium and heavy metals are present in the sediment. They are similar to those found in the Cassidaigne submarine canyon, which reinforces the hypothesis of a connection between the cave and the canyon. Recent geological studies prove a Messinian origin for the canyon and support the deep contamination model. The model is also supported by examples on Kefalonia Island (Greece) and in the Toix–Moraig system (Spain) where salt-water intrusions are observed in coastal sinkholes and sea caves. This model explains why various attempts to diminish the salinity of these brackish springs, through the construction of dams to increase head, have failed.On the Mediterranean coast, submarine karst
springs are common. Most of them are brackish and various
unsuccessful attempts in France, Greece, and Italy
indicate that it is impossible to diminish the salinity at the
spring. Based on studies on the shores of south-eastern
France and in Kefalonia (Greece), we propose a working
model that explains the mechanism of salt contamination.
During the Messinian Deep Stage (-5.9 to 5.3 Ma), a
substantial sea-level lowering in the Mediterranean
allowed the existence of cave networks extending several
hundreds of meters below the present sea level. Seawater is
now sucked into the system through these caves. This
mechanism is supported by a study of the Port Miou
underground river (Cassis, France). In the Port Miou cave
system, which extends to 250 m below sea level, titanium
and heavy metals are present in the sediment. They are
similar to those found in the Cassidaigne submarine canyon,
which reinforces the hypothesis of a connection
between the cave and the canyon. Recent geological
studies prove a Messinian origin for the canyon and support
the deep contamination model. The model is also
supported by examples on Kefalonia Island (Greece) and in
the Toix–Moraig system (Spain) where salt-water intrusions
are observed in coastal sinkholes and sea caves. This
model explains why various attempts to diminish the
salinity of these brackish springs, through the construction
of dams to increase head, have failed.


Turkish karst aquifers, 2015, Gunay G. , Guner N. , Tork K.

One third of Turkey’s surface is underlain by carbonate rocks that have been subdivided into four karst regions. The carbonate rock units are about 200 km wide along the Taurus Mountains that attain elevations of 2500 m. Karst features of western Turkey bordering the Aegean and Mediterranean seas demonstrate the tectonic, lithological and climatic controls on the occurrence, movement, and chemical characteristics of groundwater. In Turkey all karstic feature, such as lapies, caves, sinkholes, uvalas, poljes, ground river valleys developed in all karstic areas. Karstification is related not only to the thickness and to purity of limestone, climate and height but also to tectonic movements. Water resources of karst terrains of Turkey are relatively rich and as such are very important for the economic development of the country. High mountain chains, very often associated with the karst terrains, are responsible for some important and beneficial characteristics of these water resources. Four karst regions are: (1) Taurus karst region, (2) southeast Anatolia karst region, (3) central Anatolia karst region, and (4) northwest Anatolia and Thrace karst regions.


The current status of mapping karst areas and availability of public sinkhole-risk resources in karst terrains of the United States, 2015,

Subsidence from sinkhole collapse is a common occurrence in areas underlain by water-soluble rocks such as carbonate and evaporite rocks, typical of karst terrain. Almost all 50 States within the United States (excluding Delaware and Rhode Island) have karst areas, with sinkhole damage highest in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. A conservative estimate of losses to all types of ground subsidence was $125 million per year in 1997. This estimate may now be low, as review of cost reports from the last 15 years indicates that the cost of karst collapses in the United States averages more than $300 million per year. Knowing when a catastrophic event will occur is not possible; however, understanding where such occurrences are likely is possible. The US Geological Survey has developed and main-tains national-scale maps of karst areas and areas prone to sinkhole formation. Several States provide additional resources for their citizens; Alabama, Colorado, Florida, Indiana, Iowa, Kentucky, Minnesota, Missouri, Ohio, and Pennsylvania maintain databases of sinkholes or karst features, with Florida, Kentucky, Missouri, and Ohio providing sinkhole reporting mechanisms for the public.


Hidden sinkholes and karst cavities in the travertine plateau of a highly-populated geothermal seismic territory (Tivoli, central Italy), 2015,

Sinkholes and other karst structures in settled carbonate lands can be a significant source of hazard for humans and human works. Acque Albule, the study area of this work, is a Plio-Pleistocene basin near Rome, central Italy, superficially filled by a large and thick deposit of late Pleistocene thermogene travertine. Human activities blanket large portions of the flat territory covering most evidence from geological surface processes and potentially inducing scientists and public officials to underestimate some natural hazards including those connected with sinkholes. To contribute to the proper assessment of these hazards, a geomorphologic study of the basin was performed using digital elevation models (DEMs), recent aerial photographs, and field surveys. Historical material such as old aerial photographs and past geomorphologic studies both pre-dating the most part of quarrying and village building was also used together with memories of the elderly population. This preliminary study pointed out the presence of numerous potentially active sinkholes that are at present largely masked by either quarrying or overbuilding. Where this first study pointed out the apparent absence of sinkholes in areas characterized by high density of buildings, a detailed subsurface study was performed using properly-calibrated electrical resistivity tomography (ERT) and dynamic penetration measurements (DPSH), together with some borehole logs made available from the local municipality. This second study highlighted the presence of sinkholes and caves that are, this time, substantially hidden to the resolution of standard methods and materials such as aerial photographs, DEMs, and field surveys. Active sinkhole subsidence in the Acque Albule Basin may explain, at least in part, the frequent damages that affect numerous buildings in the area. The main conclusion from this study is that the mitigation of sinkhole hazard in highly populated areas has to pass through a thorough search of (hidden) sinkholes that can be masked by the Anthropocenic molding and blanketing of the territory. For these purposes, data from historical (pre-Anthropocene) documents as well as, where possible, subsurface investigations are fundamental.


Sinkholes, collapse structures and large landslides in an active salt dome submerged by a reservoir: The unique case of the Ambal ridge in the Karun River, Zagros Mountains, Iran, 2015,

Ambal ridge, covering 4 km2, is a salt pillowof Gachsaran Formationwith significant salt exposures in direct contact  with the Karun River, Zagros Mountains. The highly cavernous salt dome is currently being flooded by the  Gotvand Reservoir, second largest in Iran. Geomorphic evidence, including the sharp deflection of the Karun  River and defeated streams indicate that Ambal is an active halokinetic structure, probably driven by erosional  unloading. Around 30% of the salt dome is affected by large landslides up to ca. 50 × 106 m3 in volume. Slope  oversteepening related to fluvial erosion and halokinetic rise seems to be the main controlling factor. A total of  693 sinkholes have been inventoried (170 sinkholes/km2), for which a scaling relationship has been produced.  The depressions occur preferentially along a belt with a high degree of clustering. This spatial distribution is  controlled by the proximity to the river, slope gradient and halite content in the bedrock. A large compound  depression whose bottom lies below the normal maximum level of the reservoir will likely be flooded by  water table rise forming a lake. The impoundment of the reservoir has induced peculiar collapse structures  220–280 m across, expressed by systems of arcuate fissures and scarps. Rapid subsurface salt dissolution is  expected to generate and reactivate a large number of sinkholes and may reactivate landslideswith a significant  vertical component due to lack of basal support.


Karst environment, 2016, Culver D. C.

Karst environments can be grouped into three broad categories, based on their vertical position in the landscape. There are surface habitats, ones exposed to light; there are shallow subterranean (aphotic) habitats oft en with small to intermediate sized spaces; there are deep subterranean habitats (caves) with large sized spaces. Faunal records are most complete for caves, and on a global basis, more than 10,000 species are limited to this habitat. Hundreds of other species, especially bats, depend on caves for some part of their life cycle. A large, but most unknown number of species are limited to shallow subterranean habitats in karst, such as epikarst and the milieu souterrain superficiel. Species in both these categories of habitats typically show a number of morphological adaptations for life in darkness, including loss of eyes and pigment, and elaboration of extra-optic sensory structures. Surface habitats, such as sinkholes, karst springs, thin soils, and rock faces, are habitats, but not always recognized as karst habitats. Both aphotic karst habitats and twilight habitats (such as open air pits) may serve as important temporary refuges for organisms avoiding temperature extremes on the surface.


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