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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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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.
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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 low-mg calcite (Keyword) returned 6 results for the whole karstbase:
At Tylicz, near Krynica Spa (Polish Carpathians), spelean deposits fill fissures and caverns in Eocene flysch rocks. They occur as: (1) clastic cave sediments transformed into hard crusts due to cementation by finely crystalline low-Mg calcite, (2) drusy calcite that covers crust surfaces and fills voids in the crust and (3) colloform calcite. Two varieties of drusy calcite are distinguished: acicular and columnar. The acicular calcite is built up of crystallites forming spherulitic fans or cones. In places it is syntaxially covered with colloform calcite. The drusy calcite is low-Mg ferroan calcite with non-ferroan subzones, whereas the colloform calcite is a low-Mg non-ferroan variety. The columnar calcite crystals form fan-like bundles. Cross-sections cut perpendicular to the c-axes of columnar crystals are equilateral triangular in shape, although some have slightly curved edges. The columnar crystals have steep rhombic terminations and most have curved triangular faces, i.e. gothic-arch calcite. Saddle crystals have also been observed. The columnar crystals are composed of radially orientated crystallites whose long dimension is parallel to the c-axis. The curved crystal faces of such polycrystals are interpreted as a result of differential growth rates of the crystallites. The spelean calcites precipitated from CO2-saturated water. The high rate of CaCO3 Precipitation is thought to be responsible for the formation of radial structures. Finely crystalline calcite formed within pore spaces of clastic sediments close to the water-air interface, drusy calcite crystallized beneath the water-air interface, and colloform calcite precipitated from thin films of water

Ancient helictites and the formation of vadose crystal silt in upper Jurassic carbonates (Southern Germany), 1998, Reinhold C. ,
Speleothems and vadose crystal silt are effective indications for karstification processes in the fossil record. Upper Jurassic limestones in Southern Germany that have undergone vadose diagenesis contain on crystal margins and tips of coarse bladed calcites numerous fibrous calcite crystals, formed by abnormal growth conditions, and internal sediment within fractures and vugs, Fibrous calcite crystals grew as crusts, in fence and mesh-like arrangements. Fibrous crystals, which have a length:width ratio of greater than 1:10, are made up of stacked subcrystals composed of an alternation of hexagonal prisms and rhombohedra, They exhibit a central to somewhat eccentric capillary. Electron probe microanalysis shows low-Mg calcite mineralogy with negligible amounts of Fe, Mn, and Sr as well as dis seminated clay and metal hydroxide impurities. Stable-isotope data show relatively C-13-enriched and O-18-depleted values (delta(13)C similar to parts per thousand PDB, delta(18)O similar to -6 parts per thousand PDB), suggesting a meteoric environment and CO2 degassing as the main process of formation, Fibrous calcite crystals form from capillary fluids that are highly supersaturated with respect to calcium carbonate, contaminated with alien mineral impurities. The abnormal growth pattern is suggested to be substrate-controlled and attributed to mineral impurities that produce numerous crystallization nuclei. Fibrous calcite crystals are comparable to helictites of the filiform type that are reported only from Quaternary caves. Nevertheless, the diagenetic sequence and oxygen isotope data suggest a Late Cretaceous to early Tertiary age for their formation. The internal sediment consists exclusively of silt-size fragments of fibrous crystals and therefore is comparable to vadose crystal silt. Crystal silt is generated by the erosion of fibrous crystals both by va dose seepage and air currents. This study is the first observation of ancient helictites and related vadose crystal silt, documenting the close relationship between pore ceiling vadose cements and the generation of crystal silt

Sedimentology and geochemistry of fluvio-lacustrine tufa deposits controlled by evaporite solution subsidence in the central Ebro Depression, NE Spain, 2000, Arenas C, Gutierrez F, Osacar C, Sancho C,
The Urrea de Jalon tufa deposits constitute the 20- to 50-m-thick caprock (0.3 km(2)) of an isolated mesa. They disconformably overlie horizontal strata of the Tertiary Ebro Basin (NE Spain), which contains a thick succession of lacustrine gypsum and marls, followed by limestones, marls and, locally, fluvial sandstones and mudstones. The tufa deposits show a complex, large-scale framework of basin-like structures with centripetal dips that decrease progressively from the base to the top of the tufa succession, and beds that thicken towards the centre of the structure (cumulative wedge-out systems). These geometries reveal that the tufa deposits were affected by differential synsedimentary subsidence. Distinct onlapping depressions reflect time migration of the subsiding areas. The studied carbonates are composed mostly of low-Mg calcite, with minor quartz. Some samples have anomalously high contents of Fe, Mn and Ba that may exceed 1% (goethite, haematite and barite are present). Carbonate facies are: (a) macrophyte encrustation deposits; (b) bryophyte build-ups; (c) oncolite and coated grain rudstones; (d) non-concentric stromatolite-like structures; (e) massive or bioturbated biomicrites; and (f) green and grey marls. Facies a and c show a great variety of microbial-related forms. These facies can be arranged in dm- to 2-m-thick vertical associations representing: (i) fluvial-paludal sequences with bryophyte growths; (ii) pond-influenced fluvial sequences; and (iii) lacustrine-palustrine sequences. The Urrea de Jalon tufa deposits formed in a fluvio-lacustrine environment that received little alluvial sediment supply. Isotope compositions (delta(13)C and delta(18)O) reveal meteoric signatures and accord with such a hydrologically open system of fresh waters. The Fe, Mn and Ba contents suggest an additional supply of mineralized waters that could be related to springs. These would have been discharge points in the Ebro Depression of a regional aquifer of the Iberian Ranges. Rising groundwater caused the solution of the underlying evaporites and the synsedimentary subsidence of the tufa deposits

Carbonate Speleothems in the Dry, Inneralpine Vinschgau Valley, Northernmost Italy: Witnesses of Changes in Climate and Hydrology Since the Last Glacial Maximum, 2002, Spotl C. , Unterwurzacher M. , Mangini A. , Longstaffe F. J. ,
An interesting association of slope breccia, inactive and active tufa deposits, and speleothems is present in the central Vinschgau Valley, Italy. The occurrence of abundant carbonate cements in fractures and voids of crystalline basement rocks is unexpected considering the fact that this valley is among the driest spots in the entire Alps. Low annual precipitation of 440-530 mm coupled with frequent wind give rise to a semiarid climate and steppe vegetation along the south-facing slopes of the valley. Springs in this area are mostly supersaturated with respect to calcite, and carbonate precipitation occurs locally as tufas and, less well known because of lack of accessibility, as speleothems in the shallow subsurface. The majority of the tufa deposits and speleothems, however, are fossil. Speleothems are composed of low-Mg calcite and calcite-aragonite, respectively. Delicate growth textures including presumable annual lamination caused by pronounced changes in fluorescence intensity are preserved in both calcite and aragonite. Most calcite is a primary precipitate, but small amounts of secondary calcite replacing aragonite are common in most aragonite-bearing samples. The highly radiogenic Sr isotope composition, as well as high concentrations of U, Fe, Sr, and Mg, indicate that the groundwater from which these carbonates precipitated experienced intensive interaction with the host crystalline rocks. The very low tritium concentrations and the lack of a seasonal O isotope variation in modern spring waters, as well as their rather constant hydrochemical composition, also support this suggestion. S isotope data for dissolved sulfate and Ca and Mg sulfate precipitates indicate a sulfide source, i.e., oxidation of sulfide ore minerals in the aquifer, resulting in elevated sulfate and Fe concentrations. Th/U dating of speleothem samples using thermal ionization mass spectrometry yielded ages between 13,710 and 378 yr BP, with most ages falling in the early to middle Holocene. Although no isotopic dates are available for the tufa deposits, field evidence strongly suggests that speleothems, tufa deposits, and carbonate cements in the slope breccia were closely related. We therefore interpret the existence of these terrestrial carbonates as evidence of changes in climate since the middle Holocene. Their presence suggests a higher annual rainfall during the first half of the Holocene, possibly because of enhanced moisture transport from the Mediterranean

Floating Rafts of Calcite Crystals in Cave Pools, Central Texas, U.S.A.: Crystal Habit vs. Saturation State, 2004, Taylor Penny M. , Chafetz Henry S. ,
Calcite precipitation at the air-water interface in cave pools in central Texas (U.S.A) produces floating rafts of interconnected, low-Mg calcite crystals with individual crystal habits that range from equant (length to width = 1:1) to prismatic (4:1). Saturation state for the waters ranges from -0.19 to .35 (SIc = log IAP/K). Equant crystals precipitate from waters with a lower saturation index (SIc) and form rafts with a fused fabric whereas prismatic crystals precipitate from higher-SIc waters and form rafts with an interlaced fabric. The pools contain low-magnesium (molal Mg/Ca < 0.6), calcium-bicarbonate, and calcium-bicarbonate-nitrate type waters with temperatures that range from 13.8{degrees}C to 20.7{degrees}C and pH readings from 6.7 to 8.4. Equant euhedral crystals precipitate from water with saturation states close to equilibrium. Visible defects in the equant crystals include incomplete edges between faces and nearly circular (mean diameter 9 {micro}m) to angular holes in faces. The holes apparently result from crystallite growth around foreign objects on the crystal surface such as gas bubbles. Prismatic crystals precipitate from supersaturated water. Faces of these subhedral crystals are smaller in area than the faces of the equant crystals. No intrafacial circular holes are seen, but trigonal intercrystallite pores are common in the prismatic crystals. The variety in crystal habits, from equant to prismatic, is due to preferential growth along one crystallographic axis. Thus, in these cave pools crystal habit is related to the saturation state of the water

Kryogene Karbonate im Hhleneis der Eisriesenwelt, 2008, Sptl, C.
Progressive freezing of calcium- and bicarbonate- bearing cave waters can give rise to high supersaturation and the subsequent precipitation of microscopic calcite crystals and aggregates thereof. These particles are disseminated in the ice of ice caves and may later be concentrated by sublimation or melting of ice to form thin carbonate beds in layered ice (cryogenic carbonates). Such white to light brown, silty to fine sandy layers occur in the rear of the ice-bearing part of the Eisriesenwelt cave (Werfen, Salzburg) and were previously regarded as finely disintegrated limestone powder derived from the cave ceiling. Studies using scanning electron microscopy show that this material consists of 30-200 ?m aggregates of euhedral crystals, which, according to powder Xray diffraction analyses, are near-stoichiometric low-Mg calcite. The crystal aggregates commonly show a conspicuous flat top and resemble larger floating calcite rafts known from calcite-precipitating pools in ice-free caves. There are gradual transitions between these aggregates and skeletal crystal aggregates and (hemi)spherulitic forms, respectively. The small particle size and the skeletal crystal habit strongly argue in favour of rapid crystal growth during freezing of shallow puddles of icy water. This interpretation is corroborated by the highly positive C isotope values, which, in conjunction with the O isotope data, prove the cryogenic origin of these carbonates. The proportion of detrital contamination is very low. This study is the first report of fine-grained cryogenic speleothems in an eastalpine cave. It is supposed that such sediments are more wide spread and thicker layers may represent important paleoenvironmental marker horizons.

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