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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. ...

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

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
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
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for exposure (Keyword) returned 139 results for the whole karstbase:
Showing 46 to 60 of 139
Flared slopes revisited, 1998, Twidale C. R. , Bourne J. A. ,
Flared slopes are smooth concavities caused by subsurface moisture-generated weathering in the scarp-foot zone of hillslopes or boulders. They are well represented in granitic terrains but also developed in other massive materials such as limestone, sandstone, dacite, rhyolite, and basalt, as well as other plutonic rocks. Notches, cliff-foot caves, and swamp slob are congeners of flared slopes. Though a few bedrock flares are conceivably caused by nivation or by a combination of coastal processes, most are two-stage or etch forms. Appreciation of the origin of these forms has permitted their use in the identification and measurement of recent soil erosion and an explanation of natural bridges. Their mode of development is also germane to the origin of the host inselberg or bornhardt and, indeed, to general theories of landscape evolution. But certain discrepancies have been noted concerning the distribution and detailed morphology of flared slopes. Such anomalies are a result of structural factors (sensu late), of variations in size of catchment and in degree of exposure, and of several protective factors. Notwithstanding, the original explanation of flared slopes stands, as do their wider implications

High-resolution sequence stratigraphic correlation in the Upper Jurassic (Kimmeridgian)-Upper Cretaceous (Cenomanian) peritidal carbonate deposits (Western Taurides, Turkey), 1999, Altiner D, Yilmaz Io, Ozgul N, Akcar N, Bayazitoglu M, Gaziulusoy Ze,
Upper Jurassic (Kimmeridgian)- Upper Cretaceous (Cenomanian) inner platform carbonates in the Western Taurides are composed of metre-scale upward-shallowing cyclic deposits (parasequences) and important karstic surfaces capping some of the cycles. Peritidal cycles (shallow subtidal facies capped by tidal-Aat laminites or fenestrate limestones) are regressive- and transgressive-prone (upward-deepening followed by upward-shallowing facies trends). Subtidal cycles are of two types and indicate incomplete shallowing. Submerged subtidal cycles are composed of deeper subtidal facies overlain by shallow subtidal facies. Exposed subtidal cycles consist of deeper subtidal facies overlain by shallow subtidal facies that are capped by features indicative of prolonged subaerial exposure. Subtidal facies occur characteristically in the Jurassic, while peritidal cycles are typical for the Lower Cretaceous of the region. Within the foraminiferal and dasyclad algal biostratigraphic framework, four karst breccia levels are recognized as the boundaries of major second-order cycles, introduced for the first time in this study. These levels correspond to the Kimmeridgian-Portlandian boundary, mid-Early Valanginian, mid-Early Aptian and mid-Cenomanian and represent important sea level falls which affected the distribution of foraminiferal fauna and dasyclad flora of the Taurus carbonate platform. Within the Kimmeridgian-Cenomanian interval 26 third-order sequences (types and 2) are recognized. These sequences are the records of eustatic sea level fluctuations rather than the records of local tectonic events because the boundaries of the sequences representing 1-4 Ma intervals are correlative with global sea level falls. Third-order sequences and metre-scale cyclic deposits are the major units used for long-distance, high-resolution sequence stratigraphic correlation in the Western Taurides. Metre-scale cyclic deposits (parasequences) in the Cretaceous show genetical stacking patterns within third-order sequences and correspond to fourth-order sequences representing 100-200 ka. These cycles are possibly the E2 signal (126 ka) of the orbital eccentricity cycles of the Milankovitch band. The slight deviation of values, calculated for parasequences. from the mean value of eccentricity cycles can be explained by the currently imprecise geochronology established in the Cretaceous and missed sea level oscillations when the platform lay above fluctuating sea level. Copyright (C) 1999 John Wiley & Sons, Ltd

Radon concentration changes in the air of two caves in Poland, 1999, Przylibski T. A. ,
The paper presents spatial and seasonal radon concentration changes in the air of two caves in Poland on the basis of measurements during 1995-1997. A process of seasonal radon concentration changes in the caves' air was identified, based on research on radon occurrence in caves carried out for over 20 years. A major role in this process was ascribed to ventilation caused by atmospheric temperature changes. High radon concentrations are observed in the warm half-year (May-August), when the average air temperature exceeds the average temperature of the cave interior. Low concentrations occur, however, in the cold half-year (December-January), and a relatively sharp increase or decrease in radon concentration is related to changes in atmospheric temperatures relative to the average temperature in the cave interior. The amplitude of these radon concentration changes may reach several kBq m(-3). In the Radochowska Cave the lowest monthly radon concentration (0.06 kBq m(-3)) was recorded in December 1996, while the highest (1.37 kBq m(-3)) was observed in August 1996. In the Niedzwiedzia Cave the lowest value (0.10 kBq m(-3)) was observed in January 1997 and the highest (4.18 kBq m(-3)) was noted in March 1997. The spatial variation of radon concentrations is mainly due to the morphology of the chambers and corridors of a cave, and by the distance between the measurement point and the entrance holes. As a rule, locations further from the entrance have poorer ventilation and higher radon concentrations. (C) 1999 Elsevier Science Ltd. All rights reserved

Basement lithology and its control on sedimentation, trap formation and hydrocarbon migration, Widuri-Intan oilfields, SE Sumatra, 1999, Tonkin P. C. , Himawan R. ,
The Widuri-lntan oilfields produce from late Oligocene sandstones of the Talang Akar Formation, which were deposited in a fluid-to-deltaic setting on the NW side of the Asri Basin, offshore SE Sumatra. The Asri Basin is of rift origin and formed during the early Oligocene, with its axis oriented in a NE-SW direction. Approximately 310 million brls of oil have been produced from the fields within the 12-by-12 mile (20-by-20 km) study area. The oil occurs in a series of structural and stratigraphic traps within slightly sinuous to meandering channel sandstone bodies. The reservoir sequence (sandstone interbedded with minor mudstone and coal) overlies basement rocks, which are predominantly Cretaceous in age. Forty-nine well penetrations have shown that the basement is composed of one of four lithologies: IB hornblende granodiorite; (2) metamorphic rocks, mainly mica schist; (3) plugs of metabasalt and related volcanic rocks; or (4) dolomitic limestone. A combination of drill cuttings, sidewall and conventional cores and FMS/FMI images has been used to identify and map the distribution of basement rock type. The basement was subjected to exposure and deep weathering prior to the formation of the Asri Basin, as evidenced by the zones of surface alteration encountered during drilling. The basement palaeotopography had a strong influence on the later distribution of major fluvial channels and sand pinch-outs. Several major faults appear to be controlled by basement lithology, especially at the boundaries of granodiorite and metabasalt intrusives. An important shear zone, oriented NW-SE, appears to have offset the basement between the main Widuri and Intan fields, and was subsequently the site of silicification of the mica schists in the basement. The Lidya field is situated where the reservoir pinches out onto eroded areas of basement silicification along this shear zone. Palaeocurrents in the upper 34-2 and 34-1 channel sandstones in the Widuri field were controlled by the orientation of this basement feature . Drape and compaction ofOligocene Talang Akar Formation sediments over eroded volcanic plugs have defined or enhanced a number of structural/stratigraphic plays, including the Widuri and Chesy fields. From seismic and well evidence, the reservoir sequence at the Indri field is underlain by dolomitic limestone and exhibits a series of unusual karst-related sinkhole and collapse structures. These are circular to slightly elliptical in shape, and extend from basement level to over 900 ft vertically into the overlying Talang Akar Formation

Mesozoic dissolution tectonics on the West Central Shelf, UK Central North Sea, 1999, Clark Ja, Cartwright Ja, Stewart Sa,
3-D seismic mapping of the Upper Jurassic Kimmeridge Clay Formation on the West Central Shelf in the Central North Sea reveals a complex fault array which is constrained by seismic interpretation and well control to be of late Jurassic/early Cretaceous age. Fault shapes in plan-view range from linear to circular. Linear fault lengths are 200-300 m to 5 km, the strongly curved and circular faults range in diameter from 100-1000 m. Fault trends are apparently random and display no correlation in location or trend with basement (sub-Zechstein) structures. There is, however, a strong link between this fault pattern and the structure of the top Zechstein (top salt) surface. Linear faults occur at the edges of elongate salt walls and the circular faults lie directly above structures which have been interpreted here as tall, steep-sided salt chimneys. The salt chimneys are present only in the thick, elongate minibasins of Triassic sediment which lie between the salt walls. It is argued that salt dissolution controls the timing, location, orientation and shape of the late Jurassic/early Cretaceous faults. A model is provided to account for the development of both salt walls and chimneys. We suggest that early Triassic karstification of the Zechstein evaporites led to development of an array of circular collapse features. During the ensuing episode of Triassic halokinesis which led to minibasin subsidence and salt wall growth, salt passively 'intruded' the circular collapse features within the subsiding minibasins to form narrow salt chimneys. The resulting array of salt walls and chimneys was subject to dissolution during subsequent subaerial exposure and the late Jurassic marine transgression of the basin (creating the observed fault array), prior to sealing of the salt from circulating groundwater by compaction of the Upper Jurassic and Lower Cretaceous shales which blanket the area. (C) 1999 Elsevier Science Ltd. All rights reserved

Dedolomitization and other early diagenetic processes in Miocene lacustrine deposits, Ebro Basin (Spain), 1999, Arenas C, Zarza Ama, Pardo G,
A variety of meteoric diagenetic features reveal the development of a syngenetic karst on lacustrine deposits of the Ebro Basin. Diagenetic processes that operated on lacustrine laminated and stromatolitic carbonates include the following. (1) A first syndepositional stage with processes such as dolomitization, desiccation and related breccia formation and sulphate precipitation, either as lenticular gypsum crystals or nodules. This stage took place under progressive evaporation due to lake level fall, when the previous carbonate deposits became exposed as a supra-littoral fringe surrounding saline mud flats of adjacent sulphate depositional environments. (2) A second early diagenetic stage in which processes such as sulphate dissolution and collapse brecciation, dedolomitization, calcite spar cementation and silicification occurred as a result of meteoric water input that caused a progressive rise in lake level. Light isotopic compositions (delta(13)C and delta(18)O) of diagenetic calcites, versus heavier compositions in primary laminated and stromatolitic limestones, confirm a meteoric influence. The syngenetic karst is best developed at the boundary between two allostratigraphic units and coincided with one of the extensive stages of sulphate deposition at the end of the Early Miocene. The karst facies occurred in an area that was a low-relief barrier that separated two sites of sulphate deposition during low lake levels, This indicates that the karat development was controlled by topographic changes within the basin and record a shift from arid to wetter climatic conditions, as suggested by the overlying freshwater carbonate deposits. The presence of diagenetic features such as those described in the central Ebro Basin affecting saline lacustrine carbonates is relevant because they can be used as indicators of subaerial exposure periods in terrestrial environments and they also reveal important palaeogeographic and palaeoclimatic events of basinal extent.

Non-invasive investigation of polygonal karst features: Yorkshire Dales National Park. MSc thesis (Exploration Geophysics), 1999, Gullen T.

Resistivity, refraction and resistivity tomography methods were used to ascertain the dimensions of any sediment body present within solution dolines. Fieldwork was undertaken at two sites within the Yorkshire Dales National Park: High Mark [SD920 679] northeast of Malham Tarn, and on Ingleborough, northeast of Clapham Bottoms [SD765 722].
Results of previous studies of doline fill have been inconclusive. It has been hypothesised (Howard, unpublished) that if dolines do contain significant amounts of sediment, the fill could provide a complete palaeoenvironmental record of the Quaternary.
Resistivity studies undertaken at High Mark used an Offset Wenner array, and field data were inverted to produce a 1-D image of the subsurface. The profiles were located at the base of the doline, in the area believed to contain the greatest sediment thickness. Results suggest that the fill comprises two layers. An upper layer approximately 1 m thick is composed of poorly consolidated clayey sand with an apparent resistivity of 166m. The second layer reaches a depth of 5.6m and is more clay-rich, with an apparent resistivity of 60m. These interpretations are supported by evidence from augering. The upper 10m of limestone below the sediment has been altered during doline formation, weathering and fracturing, and has a resistivity of 220m compared to 440m for the unaltered bedrock.
Refraction profiles were undertaken at High Mark, using the hammer and plate method with a 2m geophone spacing. Profiles were located on the base, flanks and interfluves of the doline. Ground conditions prevented the acquisition of very long offset shots (>10m), and lack of these data hindered interpretation. Profiles undertaken at Ingleborough used an explosive shot placed in a 45cm-deep hole, and a 5m geophone spacing was used. Profiles were located at the base of the dolines.
Results at High Mark suggest that the limestone is overlain by 4m of sediment. The upper layer has a velocity of approximately 0.50m/ms, whereas that of the second layer is 1.19m/ms. Alteration of the upper 6m of the bedrock is indicated by a velocity of 2.00m/ms, compared to 2.99m/ms for the unaltered limestone. The bedrock surface is undulatory, possibly indicating the effects of preferential dissolution or glacial activity.
Results of the refraction surveys at Ingleborough indicate that the limestone is overlain by a single 4m-thick layer of sediment with a velocity of 0.52m/ms. Beneath this, the upper 13m of limestone is altered, with a velocity of 2.45m/ms, which increases to 3.75m/ms in the unaltered limestone below. Velocities obtained are lower than expected, but reliable imaging of the limestone was ensured by siting the profiles close to observed rock exposures. Refraction interpretations indicate that the centre of the doline is not coincident with the position predicted from observation of the surface morphology.
Resistivity tomography profiles were undertaken at the base of the dolines at both sites. A fully automated system employing a Wenner array with 25 electrodes at 5m spacings was used, and six levels were recorded. The field data were inverted and the results suggest that there are about 12.5m of sediment in the High Mark doline. The sediment is underlain by 2m of altered limestone and the bedrock base of the doline is relatively smooth.
In contrast, the thickness of sediment fill in the Ingleborough dolines is 7.5m, but the depressions are bounded by a greater thickness of altered limestone (10m). In places the limestone imaged appears to reach the surface, but is not observed in the field, indicating that minimal sediment cover is not imaged. The surface of the limestone is pitted by smaller sediment-filled depressions, possibly a feature of glacial scour.
Two profiles were forward modelled to test the reliability of the inversion model. The models were similar, but features were displaced to the right of the true section. Synthetic models were constructed to test geological hypotheses concerning the composition of the dolines. The models suggested that the dolines are relatively shallow (<12m) and are underlain by significant thicknesses of altered limestone (~10m).
The combination of results obtained suggests that dolines are not filled by significant quantities of sediment and, consequently, they cannot be used as palaeoenvironmental indicators of the Quaternary.
Jobling A. 2000. Resistivity tomography survey over a topographic depression, West Yorkshire.
BSc thesis (Geophysical Sciences), School of Earth Sciences, University of Leeds, Leeds, LS2 9JT, UK.
Three resistivity profiles were completed across a topographic depression near Garforth, West Yorkshire. The depression is roughly circular, with a radius of approximately 20m. Two profiles ran through the centre of the depression, with a third profile lying outside it. Data from these three profiles were processed, and graphs and pseudosections were compiled. The data were also inverted.
The pseudosections and inversions both showed a large, negative resistivity anomaly centred approximately beneath the surface depression. This anomaly had a resistivity difference of between 600m and 700m compared to that of the surrounding rock.
The most likely reason for this anomaly is dissolution of limestone causing development of a doline or sinkhole. The chance of the depression being an old coal mine or sand mine working has been dismissed due to the location of the site and the nature of the resistivity anomaly.


Post-Miocene subtropical karst evolution, lower Suwannee River basin, Florida, 2000, Denizman C, Randazzo Af,
Morphometric characteristics of [~]25 000 karstic depressions suggest that the last phase of the post-Miocene karstic evolution within the lower Suwannee River basin of Florida has been controlled by the lower sea-level stands of the Pleistocene and the formation of the Suwannee River. During the Pleistocene, as interglacial seas retreated, marine terraces formed by sequential sea-level lowstands and the time period of subaerial exposure diminished toward the sea. Consequently, geomorphologically younger karst landforms formed as the elevation of marine terraces decreased. The evolutionary geomorphological development of this heavily karstified region produced more frequent and/or larger and more complex depressions at higher elevations. A geographic information system analysis of morphometric and spatial distribution parameters of the karstic depressions within the lower Suwannee River basin reveals that the Florida karst is represented by broad, shallow depressions with an average density of 6.07/km2 and an average pitting index of 14.5. Morphometric and spatial distribution parameters of karstic depressions show a great variation within the lower Suwannee River area and thus preclude a simple morphoclimatic classification of karst landforms. The Tertiary carbonate rocks of the subtropical Florida karst have relatively less joint frequency and significant primary porosity, and do not produce the extreme karst landforms observed in the massive limestones of the tropics

Pedogenic and Karstic Features at the Boundaries of Bathonian Depositional Sequences in the Grands Causses Area (Southern France): Stratigraphic Implications, 2000, Charcosset P, Combes Pj, Peybernes B, Ciszak R, Lopez M,
Several exposure surfaces (D1 to D6) underlain by paleosols, paleokarstic surfaces, and subsurface paleokarsts were identified in the Middle to Upper Bathonian Calcaires a Stipites and Dolomies II Formations in southern France. Two kinds of paleosols with different degrees of maturity were recognized: simple ferruginous crusts, capping very irregular bed surfaces, and a rooted horizon. The paleokarstic surfaces are marked by nodular horizons and paleocaves. On the Cevennes shoal, the paleokarsts discontinuities are associated with synsedimentary tectonic processes, which did not extend into the overlying Dolomies II Formation. Subsurface paleokarsts were observed in the Cirque du Bout du Monde (on the Cevennes shoal) within the Calcaires a Stipites Formation, just beneath surface D5. They are characterized by stronger brecciation of the beds. Most of the paleokarstic discontinuities described in this study correspond to the boundaries of four third-order depositional sequences, Bt 1 to Bt 4 (D1 at the base of Bt 1; D2, D3, D4, and D5 capping Bt 1, Bt 2, Bt 3, and Bt 4, respectively; D6 at the top of the Dolomies II Formation). D1, D2, and D3 paleokarsts are geographically limited to the Grands Causses Graben, whereas D4, D5, and D6 are present only on the Cevennes shoal. Geographic trends of paleokarsts confirm the transgressive trend of sequences Bt 3 and Bt 4, and of the overlying Dolomies II Formation towards the shoal. D6 paleokarstic features were also observed within the uppermost part of the Dolomies II Formation in the Horst de Saint-Bresson. The latter transgressive process provides evidence for subaerial exposure of this paleostructure during the latest Bathonian-Callovian interval, induced by tectonic uplifts

The Salt That Wasn't There: Mudflat Facies Equivalents to Halite of the Permian Rustler Formation, Southeastern New Mexico, 2000, Powers Dennis W. , Holt Robert M. ,
Four halite beds of the Permian Rustler Formation in southeastern New Mexico thin dramatically over short lateral distances to correlative clastic (mudstone) beds. The mudstones have long been considered residues after post-burial dissolution (subrosion) of halite, assumed to have been deposited continuously across the area. Hydraulic properties of the Culebra Dolomite Member have often been related to Rustler subrosion. In cores and three shafts at the Waste Isolation Pilot Plant (WIPP), however, these mudstones display flat bedding, graded bedding, cross-bedding, erosional contacts, and channels filled with intraformational conglomerates. Cutans indicate early stages of soil development during subaerial exposure. Smeared intraclasts developed locally as halite was removed syndepositionally during subaerial exposure. We interpret these beds as facies formed in salt-pan or hypersaline-lagoon, transitional, and mudflat environments. Halite is distributed approximately as it was deposited. Breccia in limited areas along one halite margin indicates post-burial dissolution, and these breccias are key to identifying areas of subrosion. A depositional model accounts for observed sedimentary features of Rustler mudstones. Marked facies and thickness changes are consistent with influence by subsidence boundaries, as found in some modern continental evaporites. A subrosion model accounts for limited brecciated zones along (depositional) halite margins, but bedding observed in the mudstones would not survive 90% reduction in rock volume. Depositional margins for these halite beds will be useful in reconstructing detailed subsidence history of the Late Permian in the northern Delaware Basin. It also no longer is tenable to attribute large variations in Culebra transmissivity to Rustler subrosion

Nang Nuan oil field, B6/27, Gulf of Thailand: karst reservoirs of meteoric or deep-burial origin?, 2000, Heward A. P. , Chuenbunchom S. , Makel G. , Marsland D. , Spring L. ,
Karst reservoirs in the Chumphon Basin of the Gulf of Thailand have produced oil at well rates exceeding 10 000 BBL/d. Meteorically karstified buried hills were recognized as a potential exploration play. The Nang Nuan discovery well appeared to confirm such a play, and the concept prevailed despite the accumulation of contrary and unusual data. By the time a subsequent well had produced nearly 4 x 10(6) BBL oil, there was a desire to better understand the prospectivity of the concession. The accumulated data indicate that the highs are probably syn-rift horsts and inversion features. Karst reservoirs occur in Ratburi carbonates, and Mesozoic and Tertiary clastics, apparently unrelated to subaerial exposure. The karstification appears to be primarily of deep-burial origin, as indicated by the nature of the karst, substantial pore volumes that are difficult to account for, and temperature and flow anomalies consistent with active geothermal circulation. There are granites and hot springs in the vicinity, and abundant CO2 in this and neighbouring basins. Such deep-burial karst reservoirs have different implications for reserves estimation, prospect ranking and well completions

Stepped landscapes and their significance for general theories of landscape development, 2000, Bourne Ja, Twidale Cr,
The reasons for attributing stepped inselbergs to episodic exposure are critically reviewed and problems discussed. The evolution ofsome residuals can be dated by correlation with palaeosurface remnants preserved in adjacent terrains. The age and evolution of landscapes implied by stepped landform assemblages are incompatible with most conventional models of landscape evolution. Most examples are taken from Australian sites but reference is made to comparable forms in southern African with the implication that the principles derived from Australian landscapes are also applicable elsewhere

Radon Hazards, Geology, and Exposure of Cave Users: A Case Study and Some Theoretical, 2000, Gillmore Gavin K. , Sperrin Malcom, Phillips Paul, Denman Antony
The concerns over the risks to human health from radon in underground caves are poorly documented, unlike in workplace or domestic environments where exposures are relatively well known. In U.K. caves, radon has been identified as occurring at elevated levels; but with the exception of major show caves, its impact and risk to the many groups who use the caves have thus far received inadequate attention. This paper presents a survey performed in a relatively ?low-risk? geographical area of the United Kingdom and quantifies the risk of exposure in this cave environment. Radon levels up to 12,552 Bq m−3 were measured: Such concentrations are very high but are likely to underestimate the levels in many other parts of the cave system, for reasons associated with cave architecture and meteorology. This study confirms previous workers' conclusions that long-term users of deep caves, as opposed to rock shelters, are at risk. Annual doses to certain groups of cave users have been calculated to be as high as 120 mSv, a very high value. The study also demonstrates that there is variation both within and between caves as a result of subtleties of the bedrock geology, fault patterns, and weathering. This paper sets out a theoretical model.

Speleogenesis of sistema Cheve, Oaxaca, Mexico, 2000, Hose L. D.
The Cheve hydrologic complex in southern Mxico is the deepest known karst conduit system in the world, with a proven relief of 2540 m. The explored upper portion of the system, Sistema Cheve, extends to a depth of -1386 m. The water re-emerges from a cave in the Santo Domingo canyon, about 18 km north of the main sink. The entire cave system developed in various carbonates along (and under) the footwall of Laramide-age thrust fault. Speleogenesis of Sistema Cheve began in the Neogene or Pleistocene with exposure of a carbonate block isolated by faults. Aggressive allogenic waters entered the ground near the contact and formed mostly vertical passages until they arrived at the local base level, which was ~100 m higher than its present level. The stream removed ceilings and wall in the extensively fractured carbonates, resulting in local passage enlargement. Phreatic tubes formed in the middle and lower portions of the hydrologic system. Most of the conduits drained as downcutting continued in the Santo Domingo canyon, leaving mostly air-filled cave passages with a trunk stream and phreatic loops.

Types of karst and evolution of hydrogeologic settings, 2000, Klimchouk A. , Ford D.
Karst is treated as a specific kind of fluid circulation system capable to self-development and self-organization. Active karst may evolve at wide range of geological environments, from deep-seated (without any apparent relation to the surface) to sub-surface, and be represented by confined and unconfined circulation systems. Extrinsic factors and intrinsic mechanisms of karst development change regularly and considerably within the general cycle of geological evolution of a soluble rocks or, more specifically, within hydrogeologic cycle. The latter encompasses a period of exposure between major transgressions and is characterized by progressively expanding meteoric groundwater circulation. A broad evolutionary approach is therefore needed to differentiate between karst types, which concurrently represent distinct stages of karst development. This is also a mean to adequately classify speleogenetic settings. Evolutionary typology of karst considers the whole cycle of a formation's life, from deposition (syngenetic karst) through deep burial to exposure and denudation. The group of intrastratal karst types includes deep-seated, subjacent, entrenched and denuded karst, the latter also fall into the group of exposed karst types. Exposed karst includes also open karst which represents the pure line of exposed development, that is karst evolved solely when the soluble rock has been exposed to the surface. Exposed karst development can be interrupted by a subsequent burial (buried karst), with paleokarst formed in result, and rejuvenated by exhumation. The types of karst are marked by characteristic associations of structural prerequisites for groundwater flow and speleogenesis, flow regime, recharge mode and recharge/discharge configurations, groundwater chemistry and a degree of inheritance. Consequently, these associations generate particular types of caves.

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