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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 true velocity is ground-water flow velocity in porous interstice or cavernous opening [16].?

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KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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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 h2s (Keyword) returned 81 results for the whole karstbase:
Showing 1 to 15 of 81
Chronology of the Black Sea over the last 25,000 years, 1972, Degens Et, Ross Da,
Deep-water sediments of the Black Sea deposited during Late Pleistocene and Holocene time are distinguished by three sedimentary units: (1) a microlaminated coccolith ooze mainly consisting of Emiliania huxleyi; (2) a sapropel; and (3) a banded lutite. The base of the first unit lies at 3,000 years B.P., that of the second at 7,000 years B.P., and that of the third at least at about 25,000 years B.P. Fossils and geochemical criteria are used to decipher the environmental events of this time period. Beginning with the base of the section dated at about 25,000 years B.P. we witness the final stage of metamorphosis from anoxic marine to oxic freshwater conditions. By the time this stage ended, about 22,000 years B.P., the Black Sea had become a truly freshwater habitat. The lake phase lasted about 12,000 to 13,000 years. Sedimentation rates were in the order of 1 m/103 years, but began to decrease as sea level rose during the last 5,000 years of this phase (9,000-15,000 years B.P.). Starting at about 9,000 years B.P. and continuing to 7,000 years B.P., Mediterranean waters occasionally spilled over the Bosporus as a consequence of ice retreat and sea level rise. This marked the beginning of a gradual shift from freshwater to marine, and from well aerated to stagnant conditions. At about 7,000 years B.P. when deposition of unit 2 started, the H2S zone was well established. Sedimentation rates dropped to 10 cm/103 years. Environmental conditions similar to those of today finally became established around 3,000 years B.P., almost exactly the time when Jason and the Argonauts sailed through the Bosporus in search of the Golden Fleece

The speleogenetic role of air flow caused by convection. First contribution., 1986, Cigna Arrigo A. , Forti Paolo
In the past some authors described the speleogenetic role of convection in phreatic conditions. Similar effects exist also in the air-fiLled part of vadose passages of caves as a consequence of an air circulation due to a relevant temperature gradient; the effects can be enhanced by the presence of some acids as, e.g., H2S, H2SO4, etc. In this paper the conditions matching convection and condensation which produce typical forms, very similar to those found under phreatic conditions, are discussed both for limestone and gypsum caves.

Limestone caves form along ground-water paths of greatest discharge and solutional aggressiveness. Flow routes that acquire increasing discharge accelerate in growth, while others languish with negligible growth. As discharge increases, a maximum rate of wall retreat is approached, typically about 0.01-0.1 cm/yr, determined by chemical kinetics but nearly unaffected by further increase in discharge. The time required to reach the maximum rate is nearly independent of kinetics and varies directly with flow distance and temperature and inversely with initial fracture width, discharge, gradient, and P(CO2). Most caves require 10(4) - 10(5) yr to reach traversable size. Their patterns depend on the mode of ground-water recharge. Sinkhole recharge forms branching caves with tributaries that join downstream as higher-order passages. Maze caves form where (1) steep gradients and great undersaturation allow many alternate paths to enlarge at similar rates or (2) discharge or renewal of undersaturation is uniform along many alternate routes. Flood water can form angular networks in fractured rock, anastomotic mazes along low-angle partings, or spongework where intergranular pores are dominant. Diffuse recharge also forms networks and spongework, often aided by mixing of chemically different waters. Ramiform caves, with sequential outward branches, are formed mainly by rising thermal or H2S-rich water. Dissolution rates in cooling water increase with discharge, CO2 content, temperature, and thermal gradient, but only at thermal gradients of more than 0.01-degrees-C/m can normal ground-water CO2 form caves without the aid of hypogenic acids or mixing. Artesian flow has no inherent tendency to form maze caves. Geologic structure and stratigraphy influence cave orientation and extent, but alone they do not determine branch-work versus maze character

The Ozark region of the U.S. midcontinent is host to a number of Mississippi Valley-type districts, including the world-class Viburnum Trend, Old Lead Belt, and Tri-State districts and the smaller Southeast Missouri barite, Northern Arkansas, and Central Missouri districts. There is increasing evidence that the Ozark Mississippi Valley-type districts formed locally within a large, interconnected hydrothermal system that also produced broad fringing areas of trace mineralization, extensive subtle hydrothermal alteration, broad thermal anomalies, and regional deposition of hydrothermal dolomite cement. The fluid drive was provided by gravity flow accompanying uplift of foreland thrust belts during the Late Pennsylvanian to Early Permian Ouachita orogeny. In this study, we use chemical speciation and reaction path calculations, based on quantitative chemical analyses of fluid inclusions, to constrain likely hydrothermal brine compositions and to determine which precipitation mechanisms are consistent with the hydrothermal mineral assemblages observed regionally and locally within each Mississippi Valley-type district in the Ozark region. Deposition of the regional hydrothermal dolomite cement with trace sulfides likely occurred in response to near-isothermal effervescence of CO2 from basinal brines as they migrated to shallower crustal levels and lower confining pressures. In contrast, our calculations indicate that no one depositional process can reproduce the mineral assemblages and proportions of minerals observed in each Ozark ore district; rather, individual districts require specific depositional mechanisms that reflect the local host-rock composition, structural setting, and hydrology. Both the Northern Arkansas and Tri-State districts are localized by normal faults that likely allowed brines to rise from deeper Cambrian-Ordovician dolostone aquifers into shallower carbonate sequences dominated by limestones. In the Northern Arkansas district, jasperoid preferentially replaced limestones in the mixed dolostone-limestone sedimentary packages. Modeling results indicate that the ore and alteration assemblages in the Tri-State and Northern Arkansas districts resulted from the flow of initially dolomite-saturated brines into cooler limestones. Adjacent to fluid conduits where water/rock ratios were the highest, the limestone was replaced by dolomite. As the fluids moved outward into cooler limestone, jasperoid and sulfide replaced limestone. Isothermal boiling of the ore fluids may have produced open-space filling of hydrothermal dolomite with minor sulfides in breccia and fault zones. Local mixing of the regional brine with locally derived sulfur undoubtedly played a role in the development of sulfide-rich ore runs. Sulfide ores of the Central Missouri district are largely open-space filling of sphalerite plus minor galena in dolostone karst features localized along a broad anticline. Hydrothermal solution collapse during ore deposition was a minor process, indicating dolomite was slightly undersaturated during ore deposition. No silicification and only minor hydrothermal dolomite is present in the ore deposits. The reaction path that best explains the features of the Central Missouri sulfide deposits is the near-isothermal mixing of two dolomite-saturated fluids with different H2S and metal contents. Paleokarst features may have allowed the regional brine to rise stratigraphically and mix with locally derived, H2S-rich fluids

Along the Hornsund fault zone, South Spitsbergen (76-degrees-60'N), thermokarstic springs smell of H2S and display either growth of, or eject fragments of, organic slime. The temperature in individual springs varies between 4 and 15-degrees-C. Their rate of discharge is approximately 1 L s-1 to 18 m3 s-1, corresponding to a minimum temperature of 30-degrees-C within the base of the aquifer. The water, which contains a few ppm SO4(2-), 0.5 ppm S2-, and several thousand ppm NaCl, appears to be a mixture of turbid glacial meltwater and hot brine. Water chemistry and stable isotopes indicate that the salinity is not the result of simple dilution of modern seawater from the brackish zone beneath the coastal karst aquifer, but rather originates from a deep thermal brine component where concentrations and isotopic composition of various species are controlled by water-rock interaction in the source area of the brine. A value of DELTAdeltaS-34 of up to about 30 parts per thousand indicates that sulfide is a bioreduction product of sulfate. Scanning electron microscope (SEM) studies revealed bacteria and fungal hypha in the organic slime, and larger spherical particles (approximately 3.8 mum diameter) that display high concentrations of Fe and S. These findings demonstrate the presence of sulfate-reducing bacteria within the subpermafrost aquifer

Classification of cave dypsum deposits derived from oxidation of H2S, 1994, Buck M. J. , Ford D. C. , Schwarcz H. P.

Geochemistry of submarine warm springs in the limestone cavern of Grotta Azzurra, Capo Palinuro, Italy: evidence for mixing-zone dolomitisation, 1996, Stuben Doris, Sedwick Peter, Colantoni Paolo,
Subtidal springs in and around the submarine limestone cavern of Grotta Azzurra, at Capo Palinuro, Italy, discharge fluids which are warm (-, Na and Mg2, and enriched in Si, alkalinity, Ca2, Sr2, Mn, NH4, PO43- and H2S, relative to surrounding seawater. The compositions of the warm fluid samples collected in and around the cave define mixing lines which suggest dilution of a single thermal fluid (T >= 23[deg]C) by cool overlying seawater (T= 17-17.6[deg]C). The chemical data suggest that the proposed thermal fluid contains two components, one derived from seawater ( 10%). Excess Si, alkalinity, Ca2, Sr2 and Mn relative to seawater are likely derived from the groundwater component or dissolution/hydrothermal alteration of the host rocks. Magnesium has been removed from the seawater component in exchange for Ca2, due to dolomitisation of the limestone and/or hydrothermal alteration reactions. Saturation-state calculations suggest that the vented fluids are near saturation with respect to calcite and supersaturated with respect to dolomite. This and the presence of dolomite in the host rocks and cave-floor sediments suggest that 'mixing-zone' dolomitisation of the limestones is occurring, perhaps kinetically assisted by elevated temperature and/or bacterial mediation in the reducing subseafloor zone. One possible 'end-member' condition is considered for the thermal fluid -- zero-Mg -- which suggests an end-member temperature of 50.5[deg]C and a fluid composition derived from ~ 38% seawater and ~ 62% groundwater. The heat source for the circulating fluids is uncertain, but may involve warm underlying igneous rocks or heating via the geothermal gradient. A continuous in-situ record of vent-fluid temperature, salinity, pH and O2 concentration collected within the cavern is consistent with our interpretation of the fluid origin, and suggests that tidal forcing affects circulation and venting of the warm fluids

Initial Geologic Observations in Caves Bordering the Sibari Plain (Southern Italy), 1997, Galdenzi, S.
Geologic investigation of caves in the northern Calabria region of Italy has clarified their origin and irregular distribution. Caves and surface karst landforms are not widespread, despite the fact that the local limestones are widely exposed and surface drainage is poorly developed. The caves are located in small limestone hills and mountains around the Sibari Plain and are surrounded by low-permeability rocks. Among them is a significant shaft cave fed by a sinking stream that drains a non-karst recharge area. However, most of the caves are predominantly horizontal and have entrances at low altitudes at several levels. Their origin is due to the rising of thermal waters, which are mineralized after passing through the Neogene formations of the Sibari Plain. The caves can be considered relict hypogenic outflow caves. The main cave-forming process was probably the oxidation of H2S, favored by the mixing of thermal water and infiltrating fresh water. Oxidation of H2S has resulted in gypsum deposits within the caves.

Hydrobasaluminite and Aluminite in Caves of the Guadalupe Mountains, New Mexico, 1998, Polyak, V. J. , Provencio, P.
Hydrobasaluminite, like alunite and natroalunite, has formed as a by-product of the H2S-H2SO4 speleogenesis of Cottonwood Cave located in the Guadalupe Mountains of New Mexico. This mineral is found as the major component of white pockets in the dolostone bedrock where clay-rich seams containing kaolinite, dickite, and illite have altered during speleogenesis to hydrobasaluminite, amorphous silica, alunite, and hydrated halloysite (endellite). Gibbsite and amorphous silica are associated with the hydrobasaluminite in a small room of Cottonwood Cave. Opalline sediment on the floor of this room accumulated as the cave passage evolved. Jarosite, in trace amounts, occurs in association with the opalline sediment and most likely has the same origin as hydrobasaluminite and alunite. The hydrobasaluminite was found to be unstable at 25C and 50% RH, converting to basaluminite in a few hours. Basaluminite was not detected in the cave samples. Aluminite has precipitated as a secondary mineral in the same small room where hydrobasaluminite occurs. It comprises a white to bluish-white, pasty to powdery moonmilk coating on the cave walls. The bedrock pockets containing hydrobasaluminite provide the ingredients from which aluminite moonmilk has formed. It appears that recent cave waters have removed alumina and sulfate from the bedrock pocket minerals and have deposited aluminite and gypsum along the cave wall. Gypsum, amorphous silica and sulfate-containing alumina gels are associated with the aluminite moonmilk.

Chemoautotrophic microbial mats in submarine caves with hydrothermal sulphidic springs at Cape Palinuro, Italy, 1998, Mattison R. G. , Abbiati M. , Dando P. R. , Fitzsimons M. F. , Pratt S. M. , Southward A. J. , Southward E. C. ,
Observations were made on the distribution, morphology, and chemoautotrophic potential of microbial mats found in submarine caves of dolomitized limestone which contain hydrothermal sulphidic springs at Cape Palinuro, Italy. The distribution of microbial mats is closely associated with the flow of hydrothermal fluid from springs whose activity is intermittent and initiated during low tide. Fluid emitted from active springs in the Grotta Azzurra has a maximum temperature of 24.6 degrees C and is enriched in dissolved sulfur species (H2S, S2O32-) and dissolved gases (CH4, CO2). However, it is depleted in NaCl and dissolved O-2, in comparison with ambient seawater. This fluid is less dense and rises above the ambient seawater to form a visible thermocline and chemocline separating both lavers in the submarine caves. Microbial mats were attached to rock surfaces immersed in fluid above the chemocline and were differentiated into brown and white forms. Brown mats were composed of trichomes (4.2 0.1 mu m and 20.3 0.7 mu m in diameter) resembling the calcareous rock-boring cyanobacterium Schizothrix and clusters (6 mu m in diameter) of sarcina-like cells morphologically resembling methanogenic bacteria. White mats were composed of attached filaments resembling Beggiatoa (19.3 0.5 mu m, 39.0 1.7 mu m, and 66.9 3.3 mu m in diameter) and Thiothrix (4.2 0.2 mu m in diameter). Flexibacteria (<1 mu m in diameter) were common to both mats. Beggiatoa-like filaments were morphologically similar to those attached to rocks and the byssal threads of mussels from Lucky Strike vent field on the Mid-Atlantic Ridge, Morphological comparisons were also made with typical gliding Beggiatoa from shallow seeps in Eckernforder Bucht, Baltic Sea. White mats displayed chemoautotrophic fixation of CO2 under relatively well-oxygenated laboratory conditions (maximum rate 50.2 nmol CO2/mg dry wt/h) using internal S-0 or possibly S2O32- as electron donor. Photosynthesis may be limited in the Grotta Azzurra by insufficient illumination (6.3 x 10(-7) mu einsteins/cm(2)/s), with the possibility of Schizothrix living (at least in part) as a chemoheterotroph on while mats. Chemoautotrophic fixation of CO2 by white mats is proposed as a significant source of nutrition for benthic fauna in these caves, and has been estimated as contributing 50-70 mu mol CO2/m(2) of mat/min, as measured under laboratory conditions

Cueva de Villa Luz, Tabasco, Mexico: Reconnaissance Study of an Active Sulfur Spring Cave and Ecosystem, 1999, Hose, L. D. , Pisarowicz, J. A.
Cueva de Villa Luz (a.k.a. Cueva de las Sardinas) in Tabasco, Mexico, is a stream cave with over a dozen H2S-rich springs rising from the floor. Oxidation of the H2S in the stream results in abundant, suspended elemental sulfur in the stream, which is white and nearly opaque. Hydrogen sulfide concentrations in the cave atmosphere fluctuate rapidly and often exceed U.S. government tolerance levels. Pulses of elevated carbon monoxide and depleted oxygen levels also occasionally enter the cave. Active speleogenesis occurs in this cave, which is forming in a small block of Lower Cretaceous limestone adjacent to a fault. Atmospheric hydrogen sulfide combines with oxygen and water to form sulfuric acid, probably through both biotic and abiotic reactions. The sulfuric acid dissolves the limestone bedrock and forms gypsum, which is readily removed by active stream flow. In addition, carbon dioxide from the reaction as well as the spring water and cave atmosphere combines with water. The resultant carbonic acid also dissolves the limestone bedrock. A robust and diverse ecosystem thrives within the cave. Abundant, chemoautotrophic microbial colonies are ubiquitous and apparently act as the primary producers to the caves ecosystem. Microbial veils resembling soda straw stalactites, draperies, and u-loops suspended from the ceiling and walls of the cave produce drops of sulfuric acid with pH values of <0.5-3.0 0.1. Copious macroscopic invertebrates, particularly midges and spiders, eat the microbes or the organisms that graze on the microbes. A remarkably dense population of fish, Poecilia mexicana, fill most of the stream. The fish mostly eat bacteria and midges. Participants in an ancient, indigenous Zoque ceremony annually harvest the fish in the spring to provide food during the dry season.

Overview of the Geological History of Cave Development in the Guadalupe Mountains, New Mexico, 2000, Hill, C. A.
The sequence of events relating to the geologic history of cave development in the Guadalupe Mountains, New Mexico, traces from the Permian to the present. In the Late Permian, the reef, forereef, and backreef units of the Capitan Reef Complex were deposited, and the arrangement, differential dolomitization, jointing, and folding of these stratigraphic units have influenced cave development since that time. Four episodes of karsification occurred in the Guadalupe Mountains: Stage 1 fissure caves (Late Permian) developed primarily along zones of weakness at the reef/backreef contact; Stage 2 spongework caves (Mesozoic) developed as small interconnected dissolution cavities during limestone mesogenesis; Stage 3 thermal caves (Miocene?) formed by dissolution of hydrothermal water; Stage 4 sulfuric acid caves (Miocene-Pleistocene) formed by H2S-sulfuric acid dissolution derived hypogenically from hydrocarbons. This last episode is reponsible for the large caves in the Guadalupe Mountains containing gypsum blocks/rinds, native sulfur, endellite, alunite, and other deposits related to a sulfuric acid speleogenetic mechanism.

Hydrochemical Interpretation of Cave Patterns in the Guadalupe Mountains, New Mexico, 2000, Palmer, A. N. , Palmer, M. V.
Most caves in the Guadalupe Mountains have ramifying patterns consisting of large rooms with narrow rifts extending downward, and with successive outlet passages arranged in crude levels. They were formed by sulfuric acid from the oxidation of hydrogen sulfide, a process that is now dormant. Episodic escape of H2S-rich water from the adjacent Delaware Basin, and perhaps also from strata beneath the Guadalupes, followed different routes at different times. For this reason, major rooms and passages correlate poorly between caves, and within large individual caves. The largest cave volumes formed where H2S emerged at the contemporary water table, where oxidation was most rapid. Steeply ascending passages formed where oxygenated meteoric water converged with deep-seated H2S-rich water at depths as much as 200 m below the water table. Spongework and network mazes were formed by highly aggressive water in mixing zones, and they commonly rim, underlie, or connect rooms. Transport of H2S in aqueous solution was the main mode of H2S influx. Neither upwelling of gas bubbles nor molecular diffusion appears to have played a major role in cave development, although some H2S could have been carried by less-soluble methane bubbles. Most cave origin was phreatic, although subaerial dissolution and gypsum-replacement of carbonate rock in acidic water films and drips account for considerable cave enlargement above the water table. Estimates of enlargement rates are complicated by gypsum replacement of carbonate rock because the gypsum continues to be dissolved by fresh vadose water long after the major carbonate dissolution has ceased. Volume-for-volume replacement of calcite by gypsum can take place at the moderate pH values typical of phreatic water in carbonates, preserving the original bedrock textures. At pHs less than about 6.4, this replacement usually takes place on a molar basis, with an approximately two-fold volume increase, forming blistered crusts.

Summary of the Timing of Sulfuric-Acid Speleogenesis for Guadalupe Caves Based on Ages of Alunite, 2000, Polyak, V. J. , Provencio, P. P.
The H2SO4 caves in the Guadalupe Mountains, New Mexico, USA, such as Carlsbad, Cottonwood, Endless, Lechuguilla, and Virgin caves, formed during the late Miocene and early Pliocene (12-4 Ma). It has been demonstrated that the caves at the higher elevations are the oldest. The timing of speleogenesis was determined by the 40Ar/39Ar dating of the mineral alunite, which is a direct by-product of H2SO4 speleogenesis.

Sources et hydrosystmes karstiques des rgions arides et semi-arides, essai gographique, 2000, Nicod, Jean
SPRINGS AND KARSTIC HYDROSYSTEMS IN THE ARID AND SEMI-ARID AREAS. A GEOGRAPHICAL ESSAY - The patterns of the main springs and hydrosystems in the deserts and surroundings are sorted, according to their geomorphological situation (piedmont, coastal or inner plateau), to structure of the aquifers and working of groundwater (storage capacity, artesian systems) and to the hydrochemical criteria particularly the solute load in Mg2+, SO42- and Cl-. From the best known examples, the main problems on the genesis and working of the karstic hydro-systems in arid environment are discussed: - the incidence of tectonic stress and paleokarstic and paleoclimatic inheritances; - the recent periods of recharge (in Northern Sahara and Near and Middle East); - the interactions in ionic solutions and hyper-karstic processes: particular_ly with the strong acid, H2SO4, the "double solvency effect", and the mixing water corrosion near the salt water wedge in the coastal karsts.

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