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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. ...

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That surface film is a monomolecular film of organic compounds forming on water or grain surfaces [16].?

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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 hydrogen sulfide (Keyword) returned 28 results for the whole karstbase:
Showing 1 to 15 of 28
Dissolution of carbonate minerals in the coastal halocline is taking place in the karst terrain along the northeastern coast of the Yucatan Peninsula. The dissolution is being accelerated in cenotes (sinkholes) where sulfate reduction and oxidation of the produced sulfide is occurring. Hydrogen-sulfide concentrations ranged from 0.06 to 4 mmolal within the halocline in two sinkholes. Relative to concentrations expected by conservative mixing, fluids with high hydrogen-sulfide concentrations were correlated with low sulfate concentrations, high alkalinities, low pH values, and heavy sulfur isotope values for sulfate. Hydrogen-sulfide concentrations were less than those predicted from sulfate reduction, calculated from deficiencies in measured sulfate concentrations, indicating mobility and loss of aqueous sulfide. Fluids with low hydrogen-sulfide concentrations were correlated with very high calcium concentrations, high strontium and sulfate concentrations, slightly elevated alkalinities, low pH values, and sea-water sulfur isotope values for sulfate. Gypsum dissolution is supported by the sulfur isotopes as the major process producing high sulfate concentrations. However, oxidation of aqueous sulfide to sulfuric acid, resulting in carbonate-mineral dissolution is needed to explain the calcium concentrations, low pH values, and only slightly elevated alkalinities. The halocline may trap hydrogen sulfide that has been stripped from the underlying anoxic salt water. The halocline can act as a stable, physical boundary, holding some of the hydrogen sulfide until it is oxidized back to sulfuric acid through interaction with the overlying, oxygenated fresh water or through the activity of sulfide-oxidizing bacteria

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.

Bedrock Features of Lechuguilla Cave, Guadalup Mountains, New Mexico, 2000, Duchene, H. R.
Lechuguilla is a hypogenic cave dissolved in limestones and dolostones of the Capitan Reef Complex by sulfuric acid derived from oil and gas accumulations in the Delaware Basin of southeast New Mexico and west Texas. Most of the cave developed within the Seven Rivers and Capitan Formations, but a few high level passages penetrate the lower Yates Formation. The Queen and possibly Goat Seep formations are exposed only in the northernmost part of the cave below -215 m. Depositional and speleogenetic breccias are common in Lechuguilla. The cave also has many spectacular fossils that are indicators of depositional environments. Primary porosity in the Capitan and Seven Rivers Formations was a reservoir for water containing hydrogen sulfide, and a pathway for oxygenated meteoric water prior to and during sulfuric acid speleogenesis. Many passages at depths >250 m in Lechuguilla are in steeply dipping breccias that have a west-southwest orientation parallel to the strike of the shelf margin. The correlation between passage orientation and depositional strike suggests that stratigraphy controls these passages.

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.

Lechuguilla Cave is a hypogene cave formed by oxidation of ascending hydrogen sulfide from the Delaware Basin. A unique sediment deposit with characteristics suggesting derivation from the land surface, some 285 m above, was investigated. At this location, the observed stratigraphy (oldest to youngest) was: bedrock floor (limestone), cave clouds (secondary calcite), calcite-cemented silstone, finely laminated clay, and calcite rafts. Grain-size analysis indicates that the laminated clay deposits are composed of 59-82% clay-size minerals. The major minerals of the clay were determined by X-ray diffraction analysis and consist of interstratified illite-smectite, kaolinite, illite, goethite, and quartz. Scanning electron microscopy observations show that most of the clay deposit is composed of densely packed irregular-shaped clay-size flakes. One sample from the top of the deposit was detrital, containing well-rounded, silt-size particles. Surface soils are probably the source of the clay minerals. The small amount of sand- and silt-size particles suggests that detrital particles were transported in suspension. The lack of endellite and alunite is evidence that the clays were emplaced after the sulfuric-acid dissolution stage of cave formation. Fossil evidence also suggests a previously existing link to the surface

Hydrothermal speleogenesis: its settings and peculiar features, 2000, Dublyansky Y. V.
Three major settings of hydrothermal karst development are: endokarst, deep-seated karst, and shallow karst. Endokarst develops at great depth, where the pressure exceeds the strength of the rock and voids can exist only if they are filled with overpressured fluid, which prevents them from collapse. In the deep-seated setting hydrothermal karst develops in response to changes of pressure and temperature of upwelling fluids. Two large zones: (1) zone of carbonate dissolution and (2) zone of carbonate precipitation form within hydrothermal systems. The shallow setting encompasses the interface between thermal and low-temperature waters or the zone near the upper surface of thermal waters. Four major conditions, which create and enhance solutional capacity in hydrothermal systems are: (1) elevated temperature gradients (for carbonated waters); (2) elevated rate of discharge (for carbonated waters); (3) oxidation of hydrogen sulfide; and (4) mixing waters of contrasting chemistry. These features readily occur in the shallow hydrothermal karst setting; the largest hydrothermal caves are formed there. Morphologies and dimensions of hydrothermal caves range from pores, individual rooms, and single conduit caves to large three-dimensional mazes. Cave deposits hold clues as to their origin in their mineralogy, morphology, chemistry, isotopic properties, and fluid inclusion temperatures.

Some case studies of speleogenesis by sulfuric acid, 2000, Lowe D. J. , Bottrell S. H. , Gunn J.
Minerals that can weather to produce sulfuric acid directly or indirectly, with or without microbial mediation, occur as trace components in most carbonate sequences, but they are more concentrated at specific horizons. The latter comprise beds of atypical lithology, together termed inception horizons, and they are commonly associated with breaks between major depositional cycles. Some cycle boundaries are marked by concentrations of sulfide minerals, particularly pyrite, that are readily oxidized to generate sulfuric acid. Cycle boundaries may also be marked by the presence of primary evaporite minerals such as gypsum, and their removal by direct dissolution or by their reduction to hydrogen sulfide may be implicated in early porosity development. Though few caves in carbonate sequences are largely, or entirely, the product of calcite dissolution by sulfuric acid or of evaporite removal, such processes may play an important role in cave inception. This chapter examines a number of situations where processes other than carbonic acid dissolution have played an important role in secondary porosity generation and influenced subsequent speleogenesis.

Hydrogeologic control of cave patterns, 2000, Palmer A. N.
Cave patterns are controlled by a hierarchy of hydrogeologic factors. The location and overall trend of a cave depends on the distribution of recharge and discharge points within the karst aquifer. Specific cave patterns, i.e. branchwork vs. maze patterns, are controlled mainly by the nature of the groundwater recharge. Individual passage configurations are determined by the structural nature of the bedrock and by the geomorphic evolution of the aquifer. The origin of branchwork caves is favored by point recharge sources of limited catchment area. Floodwater recharge, especially through sinking streams, tends to produce maze caves or local mazes superimposed on branchwork caves. Through floodwater activity, anastomotic mazes form in prominently bedded aquifers, network mazes in prominently fractured aquifers, and spongework mazes in highly porous or brecciated rocks. Epikarst, network caves, and spongework caves are also produced by diffuse or dispersed infiltration into the karst aquifer, and network and spongework caves can be the product of mixing of two waters of contrasting chemistry. Ramiform caves are produced most often by rising water rich in hydrogen sulfide, which oxidizes to sulfuric acid. Deep-seated processes that help to initiate cave development include the interaction between carbonates and sulfates, which can greatly increase the solubility of dolomite, gypsum, and anhydrite, while calcite precipitates. Although tightly confined artesian conditions have long been associated with the origin of maze caves, they actually have no inherent tendency to form mazes. The slow movement of groundwater close to equilibrium with dissolved bedrock, typical of tightly confined artesian aquifers, is the least favorable setting for maze development.

Speleogenesis of the Black Hills Maze Caves, South Dakota, USA, 2000, Palmer A. N. , Palmer M. V.
Caves of the Black Hills of South Dakota, USA, are located in the Madison Limestone of Mississippian (early Carboniferous) age in a zone of diagenetic breccias and late-Mississippian paleokarst. Most of the caves are extremely complex networks with multiple stratigraphically controlled storeys. Today they are essentially hydrologic relics. Their history is as complex as the caves themselves: (1) The earliest cave openings were formed by diagenetic processes, mainly by the dissolution and reduction of sulfates. Oxidation of hydrogen sulfide produced many small and rather isolated voids lined by brecciated bedrock. (2) Late Mississippian exposure produced caves, dolines, and surface fissures, which were later filled with basal Pennsylvanian (late Carboniferous) sands and clays of the Minnelusa Formation. (3) Deposition of sedimentary strata buried these early karst features to depths of at least two kilometers. During this time, voids that had not been entirely filled by Pennsylvanian sediment were lined by a thin layer of scalenohedral calcite, and later by quartz. (4) Uplift of the Black Hills at the end of the Cretaceous Period exposed the Madison Limestone once again, allowing rapid groundwater flow through it. The earlier caves and solution pockets were enlarged at this time. (5) A thick layer of rhombohedral calcite precipitated on the cave walls, probably as the result of stagnation of groundwater caused by late Tertiary aggradation, which blocked spring openings. (6) Both before and after the calcite wall crust was deposited, deep subaerial weathering produced boxwork, with veins of calcite that had replaced earlier sulfates, as well as thick accumulations of carbonate sediment. The Tertiary cave enlargement probably involved mixing of at least two of the following water sources: artesian flow from recharge along the carbonate outcrop area, diffuse recharge through the overlying sandstone, and rising thermal water. There is evidence for all three sources, but the relative importance of each is still uncertain.

Ecological assessment and geological significance of microbial communities from Cesspool Cave, Virginia, 2001, Engel As, Porter Ml, Kinkle Bk, Kane Tc,
Microbial mats from hydrogen sulfide-rich waters and cave-wall biofilms were investigated from Cesspool Cave, Virginia, to determine community composition and potential geomicrobiological functioning of acid-producing bacteria. Rates of microbial mat chemoautotrophic productivity were estimated using [C-14]-bicarbonate incorporations and microbial heterotrophy was determined using [C-14]-leucine incubations. Chemoautotrophic fixation was measured at 30.4 12.0 ng C mg dry wt(1) h(1), whereas heterotrophic productivity was significantly less at 0.17 0.02 ng C mg dry wt(1) h(1). The carbon to nitrogen ratios of the microbial mats averaged 13.5, indicating that the mats are not a high quality food source for higher trophic levels. Ribosomal RNA-based methods were used to examine bacterial diversity in the microbial mats, revealing the presence of at least five strains of bacteria. The identity of some of the strains could be resolved to the genus Thiothrix and the Flexibacter-Cytophaga-Bacteriodes phylum, and the identity of the remaining strains was to either the Helicobacter or Thiovulum group. Two of 10 sulfur-oxidizing, chemoautotrophic pure cultures of Thiobacillus spp. (syn. Thiomonas gen. nov.) demonstrated the ability to corrode calcium carbonate, suggesting that the colonization and metabolic activity of these bacteria may be enhancing cave enlargement

The hypogenic caves: a powerful tool for the study of seeps and their environmental effects, 2002, Forti P, Galdenzi S, Sarbu Sm,
Research performed in caves has shown the existence of significant effects of gas seeps, especially CO2 and H2S, within subterranean voids. Carbon dioxide causes important corrosive effects and creates characteristic morphologies (e.g., bell-shaped domes, bubble's trails), but is not involved in the deposition of specific cave minerals. On the other hand, in carbonate environments, hydrogen sulfide when oxidized in the shallow sections of the aquifer generates important corrosion effects and is also responsible for the deposition of specific minerals of which gypsum is the most common.Studies performed in the last few years have shown that H2S seeps in caves are associated with rich and diverse biological communities, consisting of large numbers of endemic species. Stable isotope studies (carbon and nitrogen) have demonstrated that these hypogean ecosystems are entirely based on in situ production of food by chemoautotrophic microorganisms using energy resulting from the oxidation of H2S.Although located only 20 m under the surface, Movile Cave does not receive meteoric waters due to a layer of impermeable clays and loess that covers the Miocene limestone in which the cave is developed. In the Frasassi caves, where certain amounts of meteoric water seep into the limestone, the subterranean ecosystems are still isolated from the surface. As the deep sulfidic waters mix with the oxigenated meteoric waters, sulfuric acid limestone corrosion is accelerated resulting in widespread deposition of gypsum onto the cave walls.Both these caves have raised a lot of interest for biological investigations regarding the chemoautotrophically based ecosystems, demonstrating the possibility of performing such studies in environments that are easily accessible and easy to monitor compared to the deep-sea environments where the first gas seeps were discovered

Filamentous 'Epsilonproteobacteria' dominate microbial mats from sulfidic cave springs, 2003, Engel As, Lee N, Porter Ml, Stern La, Bennett Pc, Wagner M,
Hydrogen sulfide-rich groundwater discharges from springs into Lower Kane Cave, Wyoming, where microbial mats dominated by filamentous morphotypes are found. The full-cycle rRNA approach, including 16S rRNA gene retrieval and fluorescence in situ hybridization (FISH), was used to identify these filaments. The majority of the obtained 16S rRNA gene clones from the mats were affiliated with the 'Epsilonproteobacteria' and formed two distinct clusters, designated LKC group I and LKC group II, within this class. Group I was closely related to uncultured environmental clones from petroleum-contaminated groundwater, sulfidic springs, and sulfidic caves (97 to 99% sequence similarity), while group II formed a novel clade moderately related to deep-sea hydrothermal vent symbionts (90 to 94% sequence similarity). FISH with newly designed probes for both groups specifically stained filamentous bacteria within the mats. FISH-based quantification of the two filament groups in six different microbial mat samples from Lower Kane Cave showed that LKC group II dominated five of the six mat communities. This study further expands our perceptions of the diversity and geographic distribution of 'Epsilonproteobacteria' in extreme environments and demonstrates their biogeochemical importance in subterranean ecosystems

Role of fluid mixing in deep dissolution of carbonates, 2003,

The presence of cavities filled with new minerals in carbonate rocks is a common feature in oil reservoirs and lead-zinc deposits. Since groundwater equilibrates rapidly with carbonates, the presence of dissolution cavities in deep carbonate host rocks is a paradox. Two alternative geochemical processes have been proposed to dissolve carbonates at depth: hydrogen sulfide oxidation to sulfuric acid, and metal sulfide precipitation. With the aid of geochemical modeling we show that mixing two warm solutions saturated with carbonate results in a new solution that dissolves limestone. Variations in the proportion of the end-member fluids can also form a supersaturated mixture and fill the cavity with a new generation of carbonate. Mixing is in general more effective in dissolving carbonates than the aforementioned processes. Moreover, mixing is consistent with the wide set of textures and mineral proportions observed in cavity infillings

Microbial contributions to cave formation: New insights into sulfuric acid speleogenesis, 2004, Engel As, Stern La, Bennett Pc,
The sulfuric acid speleogenesis (SAS) model was introduced in the early 1970s from observations of Lower Kane Cave, Wyoming, and was proposed as a cave-enlargement process due to primarily H2S autoxidation to sulfuric acid and subaerial replacement of carbonate by gypsum. Here we present a reexamination of the SAS type locality in which we make use of uniquely applied geochemical and microbiological methods. Little H2S escapes to the cave atmosphere, or is lost by abiotic autoxidation, and instead the primary H2S loss mechanism is by subaqueous sulfur-oxidizing bacterial communities that consume H2S. Filamentous 'Epsilonproteobacteria' and Gammaproteobacteria, characterized by fluorescence in situ hybridization, colonize carbonate surfaces and generate sulfuric acid as a metabolic byproduct. The bacteria focus carbonate dissolution by locally depressing pH, compared to bulk cave waters near equilibrium or slightly supersaturated with calcite. These findings show that SAS occurs in subaqueous environments and potentially at much greater phreatic depths in carbonate aquifers, thereby offering new insights into the microbial roles in subsurface karstification

The mineral assemblage of caves within Salitrari Mountain (Cerna Valley, SW Romania): depositional environment and speleogenetic implications, 2010, Puscas Cristina M. , Onac Bogdan P. , Tamas Tudor

Eighteen minerals belonging to eight chemical groups were identified from three caves within Şălitrari Mountain, in the upper Cerna River basin (Romania) by means of scanning electron microscopy, electron microprobe analysis, and X-ray powder diffraction. One passage in the Great Cave from Şălitrari Mountain, the largest cave investigated, exhibits abnormal relative humidity and temperature ranges, allowing for a particular depositional environment. The cave floor is covered by alluvial sediments (ranging from cobble, sand, and clay to silt-sized material), bear bones, bat guano, and rubble. These materials reacted with percolating meteoric water and hydrogen sulfide-rich hypogene hot solutions, precipitating a variety of secondary minerals. Most of these minerals are common in caves (e.g. calcite, gypsum, brushite), however, some of them (alunite, aluminite, and darapskite) require very particular environments in order to form and persist. Cave passage morphologies suggest a complex speleogenetic history that includes changes from phreatic to vadose conditions. The latter was punctuated by a sulfuric acid dissolution/precipitation phase, partly overprinted by present-day vadose processes. The cave morphology and the secondary minerals associated with the alluvial sediments in these caves are used to unravel the region’s speleogenetic history.

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