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Enviroscan Ukrainian Institute of Speleology and Karstology

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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 interstitial ice is ice occurring below the surface in soil pores [16].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

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What is Karstbase?



Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

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 porosity (Keyword) returned 250 results for the whole karstbase:
Showing 16 to 30 of 250
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Satterley A. K. , Marshall J. D. , Fairchild I. J. ,
The Wilde Kirche reef complex (Early-Late Rhaetian) grew as an isolated carbonate structure within the shallow Kossen Basin. At the Triassic/Jurassic boundary a single brief(c. 10-50 ka) period of subaerial exposure occurred. The preserved karst profile (70 m thick) displays a vadose zone, enhanced dissolution at a possible palaeo-watertable (5-15m below the exposure surface), and a freshwater phreatic zone. Karst porosity was predominantly biomouldic. primary cavities and biomoulds were enlarged and interconnected in the freshwater phreatic zone; cavity networks developed preferentially in patch reef facies. Resubmegence of the reef complex allowed minor modification of the palaeokarst surface by sea floor dissolution and Fe-Mn crust deposition on a sediment-starved passive margin. Fibrous calcite (FC), radiaxial fibrous calcite (RFC) and fascicular optic calcite (FOC) cements preserved as low Mg calcite (LMC) are abundant in primary and karst dissolution cavities. FC cement is restricted to primary porosity, particularly as a synsedimentary cement at the windward reef margin. FC, RFC and FOC contain microdolomite inclusions and show patchy non-/bright cathodoluminescence. delta(18)O values ofnon-luminescent portions (interpreted as near original) are -1.16 to -1.82 parts per thousand (close to the inferred delta(18)O of calcite precipitated from Late Triassic sea water). delta(13)C values are constant ( to .2 parts per thousand). These observations suggest FC, RFC and FOC were originally marine high Mg calcite (HMC) precipitates, and that the bulk of porosity occlusion occurred not in the karst environment but in the marine environment during and after marine transgression. The HMC to LMC transition may have occurred in contact with meteoric water only in the case of FC cement. The most altered (brightly luminescent) portions of RFC/FOC cements yield delta(18)O = -2.44 to -5.8 parts per thousand, suggesting HMC to LMC alteration at up to 34 degrees C, in the shallow burial environment at depths of 180-250 m. Abundant equant cements with delta(18)O = -4.1 to -7.1 parts per thousand show crisp, uniform or zoned dull luminescence. They are interpreted as unaltered cements precipitated at 33-36 degrees C at 200-290 m burial depth, from marine-derived fluids under a slightly enhanced geothermal gradient. Fluids carrying the equant cements may have induced the HMC to LMC transition in the fibrous cements

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Palmer A. N. , Palmer M. V. ,
The Kaskaskia paleokarst, part of the Mississippian-Pennsylvanian unconformity in North America, is typified by sinkholes, fissures, and dissolution caves at and near the top of the Kaskaskia Sequence (Madison Limestone and equivalents) and is covered by basal Absaroka siliciclastics (Chesterian to Morrowan). In the Rocky Mountains and Black Hills of the northwestern U. S. A. it postdates earlier features produced by sulfate-carbonate interactions, including breccias, dissolution voids, bedrock alteration, and mineralization. Both the paleokarst and earlier features have been intersected by post-Laramide caves. Ore deposits, aquifers, and petroleum reservoirs in the region are also concentrated along both the paleokarst horizons and earlier sulfate-related features. Each phase of karst modified and preferentially followed the zones of porosity and structural weakness left by earlier phases, producing an interrelated complex of now-relict features. All should be considered together to explain the present aspect of the paleokarst

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Galdenzi S, Menichetti M,
The caves of the Umbria and Marche regions in central Italy are made up of three-dimensional maze systems that display different general morphologies due to the various geological and structural contexts. At the same time, the internal morphologies of the passages, galleries, and shafts present some similarity, with solutional galleries characterized by cupolas and blind pits, anastamotic passages, roof pendants, and phreatic passages situated at different levels. Some of these caves are still active, as is the case for Frassassi Gorge, Parrano Gorge, and Acquasanta Terme, with galleries that reach the phreatic zone, where there is a rising of highly mineralized water, rich in hydrosulfydric acid, and with erosion of limestone walls and the formation of gypsum. Elsewhere there are fossil caves, such as Monte Cucco and Pozzi della Piana, where large speleothems of gypsum are present 500 m or more above the regional water table. In all of these important karst systems it is possible to recognize basal input points through fracture and intergranular porosity networks at the base of the oxidizing zone in the core of the anticline, where mineralized water rises up from the Triassic evaporitic layers in small hydrogeological circuits. Different underground morphologies can derive from the presence of a water table related to an external stream or from the confined setting of the carbonate rocks, underlying low permeable sedimentary cover, where artesian conditions can occur

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Worthington S. R. H. , Ford D. C. ,
Major ion concentrations in 404 springs in carbonate strata were found to exhibit a wide range in sulfate values. Sulfate concentrations are often much larger than would be expected from the analysis of samples from surface outcrops. Springs in the Sierra Madre Oriental (Mexico), the Rocky Mountains Front Range (Canada), and the Peak District (England) show similarities in sulfate concentration and in spatial distribution. Springs with high sulfate concentrations are found close to base level and are thermal. Springs with low sulfate concentration are found at higher elevations above base level and are not thermal. There is a direct relationship between sulfate concentration and spring temperature, and an inverse relationship with discharge. The results from the three areas described support a model of local and regional flow patterns, with deep regional flow providing the warm sulfate-rich water. The initial fracture porosity development in these aquifers may owe as much to the removal of sulfur minerals as to the removal of carbonate minerals. High sulfate values are frequently found in carbonate aquifers, so this model may be of widespread applicability

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Wicks C. M. , Herman J. S. ,
Coastal karst aquifers have highly variable distributions of porosity and permeability. The ability to assess the volume of aquifer occupied by freshwater in coastal karst aquifers is limited by both the lack of understanding of the effect that regions of cavernous porosity and permeability have on the configuration of the saline-freshwater mixing zone and by the limited knowledge of the location of the cavernous regions. A dual-density ground-water flow and solute transport model was used to explore the effect that the depth, lateral extent, and proximity to the coast of zones of high porosity and permeability has on the configuration of the saline-freshwater mixing zone. These aquifer heterogeneities tend to shift the mixing zone upward relative to the position it would have in aquifers with homogeneous porosity and permeability, Zones of high porosity and permeability located at positions shallow in the aquifer or nearer to the coast had the greatest effect. In fact, for the conditions modeled, position was more important in modifying the configuration of the mixing zone than was changing the ratio of the intrinsic permeability of the cavernous zone to the aquifer matrix from 100 to 1000. Modeling results show that ground-water flow is concentrated into the zones of high porosity and permeability and that flow configuration results in steep salinity gradients with depth, Field observations of the location of the halocline and of step changes in ground-water composition coincident with regions of cavernous porosity in coastal karst aquifers corroborate the model results, In a coastal setting with saline water intruding into an aquifer, the effect of cavernous porosity and associated high permeability is to decrease the volume of aquifer in which freshwater occurs by a greater degree than would occur in an aquifer with homogeneous porosity and permeability

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Bonacci O,
The hydro-electric power plant (HEPP) which will exclusively use water from a karst underground storage basin will be built in the vicinity of the abundant karst spring Ombla in Croatia. This paper presents the results obtained by hydrogeologic, hydrologic and hydraulic investigations related to the principles of ground water circulation in the karst. The analyses included the determination of the effective porosity n(e) of the karst aquifer and the definition of the volume of large conduits and small fractures in the karst which form the aquifer volume. The position and dimensions of large karst conduits have also been defined. It was established that in three small springs, Zaton, Zavrelje and Slavljan, water overflows from the Ombla Spring in periods of high ground water levels, It was also discovered that at certain periods the Dupuit expression for steady-state flow in an unconfined aquifer can be used. In accordance with this, it was possible to determine the values of hydraulic conductivity, K (in m s(-1)), for the Ombla aquifer. They range from 2 x 10(-3) to 5 x 10(-3) m s(-1) and are inversely proportional to the Ombla Spring discharge. Continuous measurements of the ground water level by several piezometers located in the karst hinterland of the Ombla Spring and simultaneous measurement of the discharge made it possible to define discharge curves of the Ombla Spring dependent upon the ground water levels at Various locations. Characteristic features of the discharge curves made the identification of the position and dimensions of the main karst conduits possible

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Martini J. E. J. , Eriksson P. G. , Snyman C. P. ,
Pb-Zn-F deposits occur in the very late Archaean (2.55 Ga) shallow marine dolostone of the relatively undeformed Campbellrand and Malmani Sub-groups, which are overlain unconformably by the lower Proterozoic Postmasburg and Pretoria Group siliciclastics. They consist of stratiform deposits formed by replacement and porosity-filling, as well as pipes, ring-shaped and irregular bodies associated with collapse breccia. In the Transvaal basin the latter were generated during the karst denudation period between the deposition of the Chuniespoort Group (ending at similar to 2.4 Ga) and of the Pretoria Group (starting at 2.35 Ga). A part of these mineralisations were overprinted by the metamorphism of the Bushveld Complex intrusion at 2.06 Ga. In the Transvaal basin, the age of the mineralisation is constrained between the start of the Pretoria Group deposition and the Bushveld intrusion. It is concluded that, although most of the mineralisations are characteristic of the Mississippi Valley-type, some of the northernmost occurrences, rich in siderite, are less typical. A classic genetic model is proposed. In an environment characterised by tensional tectonics and basin development, brines of basinal origin were heated by circulation into pre-Chuniespoort rocks, leached metals from the rocks they permeated, and rose as hydrothermal plumes. At relatively shallow depth they deposited minerals after mixing with water of surficial origin

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Juhasz E. , Korpas L. , Balog A. ,
Platform carbonates of the Upper Triassic Dachstein Limestone in Naszaly Hill have been karstified extensively over the past 200 million years. They provide an excellent example of polyphase karstic diagenesis that is probably typical of many subaerially exposed carbonate sequences. Seven karstic phases are recognized in the area, each of which include polyphase karstic events. The first karst phase was associated with the Lofer cycles. Meteoric waters caused dissolution; enlarged fractures and cavities were filled by marine and/or vadose silts and cement. The second karst phase was caused by local tectonic movements. Bedding-plane-controlled phreatic caves were formed, and filled by silts. The third karst phase lasted from the end of the Triassic to the Eocene. This was a regional, multiphase karstic event related to younger composite unconformities. Bauxitic fill is the most characteristic product of this phase. The karst terrain reached its mature or senile stage with very little porosity. Narrow veins and floating rafts of white calcite marks karst phase 4, which resulted from hydrothermal activity associated with Palaeogene magmatism. The early Rupelian phase of Alpine uplift caused large-scale rejuvenation of the former karst terrain (karst phase 5). Subsequently Naszaly Hill was buried as an area of juvenile karst with significant porosity. A second period of hydrothermal activity in the area (karst phase 6) was induced by Miocene volcanism, which resulted in wide, pale green calcite veins. Finally karst phase 7 was of tectonic origin. Following the most recent, Miocene uplift of the Naszaly Hill, the carbonates have again become the site of vadose karst development

Geochemical models for the origin of macroscopic solution porosity in carbonate rocks, 1995,
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Palmer A. N.

Foreword, 1995,
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Budd A. D. , Saller A. H, Harris P. M.

Application of Thermography of Karst Hydrology, 1996,
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Campbell C. W. Abd El Latif M. , Foster Jo. W.
Nearly 3000 km of Belize display well-developed karst that occurs dominantly on Cretaceous limestones distributed on the periphery of the Maya Mountains. Other exposed carbonates in Belize, sharing the same tropical climate and heavy rainfall, are not karsted. The Mayas represent a horst structure raised by movement of the Caribbean-North American plate boundary. In excess of 150 km of large cave passage has been mapped, often exhibiting multi-level development likely related to this regional tectonic motion. Passages are dominantly trunk conduits solutionally bored through the lower-lying limestones by integrated allogenic streams from the Mayas. Other large, independent caves and collapse chambers are also known. Limited U-series dating of speleothem gives minimum ages of 176 KaBP for cave development. The karst surfaces are dominated by disaggregated remnants of previous fluvial networks, but also contain spectacular collapse dolines. The karst aquifers appear to be solutionally open systems of relatively high porosity (>1%). Boosting of carbon dioxide levels above surface soil CO2 occurs within aquifers, perhaps due to decay of washed-in vegetation. Mean solutional erosion is estimated at 0.10-0.13 m/Ka for these karsts.

The applicability of numerical models to adequately characterize ground-water flow in karstic and other triple-porosity aquifers, 1996,
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Quinlan J. F. , Davies G. J. , Jones S. W. , Huntoon P. W.

The influence of bedding planes on the development of karst caves (in Slovenian and with an English summary and abstract), PhD thesis, 1996,
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Knez, M.

There have been much less researchers looking for the initial water ways in karst along the bedding-planes than those who deduced the origin of cave channels from tectonic structures. The aim of my research was to focus scientific attention on the sphere where the answers within the sedimentology might be expected. The study identified that the basic idea of bedding-plane importance at the initiation of cave channels was correct but also, that the interrelation is different from how it had been supposed. Single lithological, petrological or stratigraphical parameters of the inception are only partly known, or merely guessed. My research threw light on the problem of initial channels met in Velika dolina in Skocjanske jame. Cave passages, or their fragments and other traces of the underground karstification do not appear scattered at random on the walls but they are obviously gathered along a small number of so-called bedding-planes.
The basic working method was to locate the phreatic channels or their fragments, to sample and microscope those parts of the layers adjacent to a bedding-plane. Somewhere a whole layer was considered. Other methods were: regional distribution of caves, photographing, inventarisation and classification of speleogens and complexometry, the latter providing the purity of limestones.
The original channels are practically gathered along only three formative bedding-planes (out of 62 measured); their close vicinity differs from the others in several important properties: typically damaged rock, higher level of calcium carbonate, smaller porosity and others. Consequently the mentioned concordance cannot possibly be only apparent.
From the lithological point of view, I got neither substantial argument nor explanation for selective karstification. However, it was identified that at least in respect of a concrete example from Velika dolina, the inception started along interbedded slides that without doubt pushed the beds aside leaving an interval.

Geochemical and depth controls on Microporosity and cavity development in the Maynardville limestone: Implications for groundwater, 1997,
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Shevenell L. , Goldstrand P. M.

Dedolomitization as a driving mechanism for karst generation in Permian Blaine formation, southwestern Oklahoma, USA, 1997,
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Raines M. A. , Dewers T. A. ,
Cyclic deposits of Permian shales, dolomites, and halite and gypsum-bearing strata in the Blaine Formation of Southwestern Oklahoma contain abundant karst features. The present study shows that an important mechanism of karst development in these sequences is dedolomitization, wherein gypsum and dolomite in close spatial proximity dissolve and supersaturate groundwaters with respect to calcite. The net loss of mass accompanying this process (dolomite and gypsum dissolution minus calcite precipitation) can be manifest in secondary porosity development while the coupled nature of this set of reactions results in the retention of undersaturated conditions of groundwater with respect to gypsum. The continued disequilibrium generates karst voids in gypsum-bearing aquifers, a mineral-water system that would otherwise rapidly equilibrate. Geochemical modeling (using the code PHRQPITZ, Plummer et al 1988) of groundwater chemical data from Southwestern Oklahoma from the 1950's up to the present suggests that dedolomitization has occurred throughout this time period in evaporite sequences in Southwestern Oklahoma. Reports from groundwater well logs in the region of vein calcite suggest secondary precipitation, an observation in accord with dedolomite formation In terms of the amounts of void space produced by dissolution, dedolomitization can dominate gypsum dissolution alone, especially in periods of quiescent aquifer recharge when gypsum-water systems would have otherwise equilibrated and karst development ceased. Mass balance modeling plus molar volume considerations show that for every cubic cm of original rock (dolomite plus gypsum), there is 0.54 cm(3) of calcite and 0.47 cm(3) of void space produced Only slightly more pore space results if the dedolomitization reaction proceeds by psuedomorphic replacement of dolomite by calcite than in a reaction mechanism based on conservation of bicarbonate

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