Community news

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 cave marble is banded deposit of calcite or aragonite capable of taking a high polish [10]. see also flowstone; onyx marble.?

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

What is Karstbase?

Search KARSTBASE:

keyword
author

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;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for diffraction (Keyword) returned 44 results for the whole karstbase:
Showing 1 to 15 of 44
Karstic Fills in the Clusette Tunnel (Jura of Neuchatel Switzerland)., 1975, Meia Jean, Pochon Michel
The piercing of a road tunnel in the flank of a limestone (Malm) anticline in the Neuchatel Jura uncovered karstic forms transformed for the most part, by decarbonated soils. Mineralogical analysis of these latter, through the use of X-ray diffraction, reveals a great analogy with the surface soils. At more than 200 meters depth, the same allochtone mineralogical suite of aeolian origin which constitutes the largest part of the soils of the High Jura Mountains in Switzerland, is found: an abundance of ferriferous chlorite, and of quartz, plagioclase and potassic feldspar. The various factors favouring this deep infiltration are discussed.

Quill Anthodites in Wyanbene Cave, Upper Shoalhaven District, New South Wales, 1978, Webb J. A. , Brush J. B.

Anthodite fragments collected at Frustration Lake in Wyanbene Cave were examined by x-ray diffraction and scanning electron microscope, and found to be both calcite and aragonite. The aragonite quills are original; some of the calcite ones represent overgrowths of aragonite, but others may have formed as original calcite or by transformation of aragonite.


On the Wad-Minerals from the Cavern Environment., 1983, Kashima Naruhiko
The wad-minerals from limestone caves of Yugoslavia, China and Japan were studied. X-ray diffraction analysis revealed five minerals; birnessite, 10A-manganite, pyrolusite, todorokite and goethite. The heavy metal elements, Mn, Zn, Fe and Cr have been detected by X-ray fluorescence analysis and their contents were roughly determined. The condensation water introduced directly from the covering soils formed by the continental weathering and the deriving corrosive water interaction with limestone could be the input sources of manganese and other metal elements into the system.

On some cave minerals from Northern Norway., 1995, Lauritzen Steinerik, Onac Bogdan Petroniu
The present paper aims to point out the results of 31 samples from some Norwegian caves that have been analysed with respect to their mineralogical composition. Identification of the minerals was done by X-ray diffraction, thermal, infrared spectroscopy and scanning electron microscopy. Seventeen minerals were identified belonging to 4 groups: carbonates, sulphates, oxides-hydroxides and silicates.

Evidence for Geomicrobiological Interactions in Guadalupe Caves, 2000, Northup, D. E. , Dahm, C. N. , Melim, L. A. , Spilde, M. N. , Crossey, L. J. , Lavoie, K. H. , Mallory, L. M. , Boston, P. J. , Cummingham, K. I. , Barns, S. M.
Caves in the Guadalupe Mountains offer intriguing examples of possible past or present geomicrobiological interactions within features such as corrosion residues, pool fingers, webulites, u-loops, and moonmilk. Scanning electron microscopy, transmission electron microscopy, molecular biology techniques, enrichment cultures, bulk chemistry, and X-ray diffraction techniques have revealed the presence of iron- and manganese-oxidizing bacteria in corrosion residues, which supports the hypothesis that these organisms utilize reduced iron and manganese from the limestone, leaving behind oxidized iron and manganese. Metabolically active populations of bacteria are also found in punk rock beneath the corrosion residues. Microscopic examination of pool fingers demonstrates that microorganisms can be inadvertently caught and buried in pool fingers, or can be more active participants in their formation. Enrichment cultures of moonmilk demonstrate the presence of a variety of microorganisms. Humans can have a deleterious impact on microbial communities in Guadalupe caves

LOW-TEMPERATURE ACID WEATHERING IN NEWHAVEN, SUSSEX, UNITED KINGDOM, AND ITS APPLICATION TO THEORETICAL MODELING IN RADIOACTIVE WASTE-DISPOSAL SITES, 2000, De Putter T, Bernard A, Perruchot A, Nicaise D, Dupuis C,
Tertiary weathered sediments located immediately to the west of the harbor at Newhaven, Sussex, UK, were investigated by examination of major and trace elements by scanning electron microscope (SEM), microprobe, and inductively coupled plasma mass spectrometer (ICP-MS), and the mineralogy was studied by optical petrography, X-ray diffraction (XRD), transmission electron microscope (TEM), selective leaching, and thermodynamic modeling. Studied outcrops experienced acid leaching by sulfuric acid percolating downward through Tertiary sediments overlying Cretaceous chalk. The progressive neutralization of the percolating acid fluids resulted in 'sequentially' layered neoformation of minerals: jarosite, iron oxides, aluminous minerals (sulfates, oxyhydroxides), gypsum, and Fe-Mn oxides. Substantial agreement was found between field observations and mineral assemblages obtained by modeling with the program CHILLER. These results suggest that the initial assumptions on the weathering process and mechanisms are correct. The relevance and implications of this study in the modeling of future denudation and weathering processes of radioactive waste-disposal sites (both deeply buried sites for high-level waste and surface sites for low-level waste) are discussed. Neoformed phases, such as jarosite, aluminous minerals, and silico-aluminous gels may play a significant role in the efficient trapping of mobilized pollutant radionuclides

DETRITAL ORIGIN OF A SEDIMENTARY FILL, LECHUGUILLA CAVE, GUADALUPE MOUNTAINS, NEW MEXICO, 2000, Foos Am, Sasowsky Id, Larock Ej, Kambesis Pn,
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

AUTHIGENESIS OF TRIOCTAHEDRAL SMECTITE IN MAGNESIUM-RICH CARBONATE SPELEOTHEMS IN CARLSBAD CAVERN AND OTHER CAVES OF THE GUADALUPE MOUNTAINS, NEW MEXICO, 2000, Polyak Victor James, Guven Necip,
Trioctahedral smectite is a constituent of Mg-rich carbonate crusts and moonmilks (pasty deposits) in caves of the Guadalupe Mountains of southeastern New Mexico. Energy dispersive X-ray microanalysis of individual crystallites and their aggregates along with the X-ray diffraction analysis indicates that the smectite is probably stevensite. Saponite is likely present in some samples also. The smectite is intimately associated with dolomite crusts and huntite moonmilks in Carlsbad Cavern, Lechuguilla Cave, and other dolostone caves. Clay particles appear as fibers and films, with aggregates comprising decimicron-sized filamentous masses that envelop crystals of dolomite, huntite, and magnesite. The occurrence of smectite is related to the genesis of the Mg-rich carbonate minerals. In water films, progressive evaporation and carbon dioxide loss results in the sequential precipitation of Mg-rich calcite, aragonite, dolomite, huntite, and magnesite. This sequence of carbonate precipitation removes Ca and greatly increases the Mg/Ca ratio in the solutions. Silica is commonly available probably because of high pH conditions, and consequently, smectite forms in the Mg-rich alkaline environment. Along with the Mg-rich carbonate minerals, opal, quartz, and uranyl vanadates may precipitate with the smectite

HALLOYSITE FROM KARST SEDIMENTS OF THE KONEPRUSY AREA: EVIDENCE FOR ACID HYDROTHERMAL SPELEOGENESIS IN THE BOHEMIAN KARST, CZECH REPUBLIC, 2000, Melka K . , Suchy V. , Zeman A. , Bosak P . , Langrova A .

(Pre)-Cretaceous sediments that fill extensive hydrothermal dissolution cavities in Devonian limestones in the Certovy schody Quarry contain locally abundant halloysite clays. In most samples halloysite coexists with metahalloysite and kaolinite that form snowy-white and blue-green masses intimately intergrown with manganese oxides. The determination of members of kaolinite group minerals was the main purpose of this study. X-ray diffraction method and thermal analyses enabled to differentiate halloysite from metahalloysite and kaolinite. Tubular morphology of halloysite was observable in electron micrographs. A study of the stored material confirmed continuous transition from the halloysite form over interstratified states (mixed-layer halloysite-metahalloysite crystal structure) to metahalloysite. Field observations indicate that halloysite formed due to selective in situ hydrothermal alteration of clayey matrix of quartz sandstone and/or breccias of unclear original composition that occur within the sedimentary fill. The proposed model for halloysite formation involves alteration by warm (< 80°C) acid solutions that migrated through the system of tectonic fractures, dissolved limestone host and altered overlying sedimentary members that collapsed into the resulting hydrothermal depressions. Since halloysite partially replaced also Cenomanian sediments, the hydrothermal alteration must have occurred only during post-Cenomanian time.


Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's cave, 2001, Cacchio Paola, Cappuccio Giorgio, Ercole Claudia, Lepidi Aldo
Bacteria make a significant contribution to the accumulation of carbonate in severa! natural habitats where large amounts of carbonates are deposited. However, the role played by microbial communities in speleothem formation (stalactites, stalagmites etc.) in caves is still unclear. In bacteria carbonate is formed by autotrophic pathways, which deplete CO2 from the environment, and by heterotrophic pathways, leading to active or passive precipitation. We isolated cultivab!e heterotrophic microbial strains, able to induce CaCO3 precipitation in vitro, from samples taken from speleothems in the galleries of Stiffe's cave, L'Aquila, Italy. We found a large number of bacteria in the calcite formations (1 x 104 to 5 x 109 cells g-1). Microscopic examination, in laboratory conditions at different temperatures, showed that most of the isolates were able to form calcium carbonate microcrystals. The most crystalline precipitates were observed at 32C. No precipitation was detected in un-inoculated controls media or in media that had been inoculated with autoclaved bacterial cells. X-ray diffraction (XRD) analysis showed that most of the carbonate crystals produced were calcite. Bacillus strains were the most common calcifying isolates collected from Stiffe's Cave. Analysis of carbonate-solubilization capability revealed that the non-calcifying bacteria were carbonate solubilizers.

NORDSTRANDITE IN BAUXITE DERIVED FROM PHONOLITE, LAGES, SANTA CATARINA, BRAZIL, 2001, Dani N, Formoso Mll, Decarreau A, Meunier A,
Nordstrandite from Lages represents the first occurrence of this mineral in an oxisoil that does not involve the influence of a calcareous substrate. This is also the first reported occurrence in Brazil. Nordstrandite occurs near the city of Lages only in the weathered bedrock facies, mostly where the circulation of meteoric water is restricted. There is also a close association between nordstrandite and the weathering of modified pseudoleucite structures. The interaction of meteoric water and feldspathic alkaline country rock with uncommon texture and mineralogy (rich in nepheline, sodalite, nosean, analcime and natrolite) promotes the development of solutions enriched in alkaline ions with basic pH, necessary to form nordstrandite. A detailed study by X-ray diffraction (XRD) and infrared (IR) spectroscopy in natural or chemically leached samples was performed to identify the Al(OH)3 polymorphs of gibbsite and nordstrandite

On the genetic conditions of black manganese deposits from two caves of Eastern Serbia., 2001, Ljubojevic V. , Pafevski A. , Calicljubojevic J.
Portions of cave passages often have a black colour due to manganese deposits that occur as coatings on cave walls and ceilings, on clastic sediments, as well as on speleothems. On samples from the cave Buronov Ponor chemical analysis, infrared spectroscopy. X-ray diffraction and DTA analysis confirmed the presence of birnessite. In cave Cerjanska Pecina, the presence of manganese compounds in the black coating has been confirmed by chemical tests. In both caves it has been noted that cave passages with black coating have a distinct morphology. They are highly weathered showing an abundance of sharp prolusions, potholes in the streambed and scallops. The paper studies these occurrences and the possible link between the manganese deposition, hydrology and morphology of the passages and petrologic composition. Although this link was not identified, some interesting questions regarding manganese deposition arose. It remains unclear why manganese deposition is limited only to a certain part of cave Cerjanska Pecina, and what caused the cyclicity in manganese deposition in the cave Buronov ponor. manganese deposits, chemical analysis, speleomorphology

Soil types and eolian dust in high-mountainous karst of the Northern Calcareous Alps (Zugspitzplatt, Wetterstein Mountains, Germany), 2003, Kufmann C. ,
This, study deals with the soil formation on pure limestone in the high-mountainous karst of Wetterstein Mountains (Northern Calcareous Alps). The study area in detail covers the alpine (2000 to 2350 in) and the subnivale zone (2350 to 2600 in) of Zugspitzplatt, a tertiary paleosurface situated next to the highest summit of Germany (Zugspitze 2963 in). The formation of autochthonous soils is determined by the following parameters: uniform geology and geochemistry of Triassic limestone (CaCO3 MgCO3 greater than or equal to 98%), variable substrata (solid rock, debris, local moraine), hypsometric pattern of vegetation modified by microclimate and aspect, variety of micro-environments in karst relief. In the subnivale zone, only leptosols (lithic, skeletic) and regosols (calcaric, humic) occur, whereas in the alpine zone different stages of folic histosols and rendzic leptosols prevail due to the diversity of vegetation. The purity of limestone prevents a distinct contribution of residues to soil formation. Instead of expected A-B-C profiles, the residues are mixed with organic matter of folic horizons (O-OB-C). Only in karst depressions or on local moraines small Bt horizons (2 to 5 cm) occur. They mark a developed stage of folic histosol (O-OB-Bt-C) representing the climax of autochthonous mineral soil genesis in the study area. Special features are brown deposits (mean thickness 30 cm) covering large parts of the alpine zone. On the basis of mineralogical (X-ray diffraction, heavy minerals) and pedological data (grain size, soil chemistry), eolian origin is indicated. The resulting soils are classified as loess loam-like cambisols (Ah-Bw-2(Bt)-2C) and are related to late glacial loess deposition (Egesen-Stade of Younger Dryas). The abundance of mica and silt in the surface layers and the grain size distribution of snow dust samples prove that dust influx by southerly winds is still continuing. The major sources for both late glacial and present-day dust are magmatic and metamorphic rock formations of the Central Alps. Additionally, local dust transport from adjacent outcrops of Jurassic and Lower Cretaceous sediments is evident. (C) 2003 Elsevier Science B.V. All rights reserved

Surface sediment characteristics and tower karst dissolution, Guilin, southern China, 2003, Tang Tao,
Dissolution of extensive outcrops of limestone and dolostone in humid tropical and subtropical southern China produced numerous caves and residual hills that are referred as tower karst. This study identifies and relates the physical and chemical characteristics of the surface sediment with the limestone bedrock in Guilin to assess the influence of the limestone dissolution process on sediment composition.The results of this study indicated that (i) both limestone and dolostone of the region are very pure (99.5% and 98.5% of CaCO3 and MgCO3, respectively); (ii) the material composition of limestone and dolostone is different from that of soil and sediment of the region: constituents of surface sediments are highly related with the clastic sedimentary rocks, such as the mudstone, but show negative correlation with limestone and dolostone; (iii) the limestone formations are highly resistant to physical weathering and disintegration; their durability versus physical weathering and their high susceptibility to chemical dissolution account for why residual towers can form and persist; (iv) a dual-zone environmental structure exists vertically downward from the surface in Guilin: the zone of unconsolidated clastic sediments that is predominantly acidic, and the zone of karstified limestone that is predominantly basic. The evidence suggests that the environment and processes differ in these two zones. The chemical dissolution of limestone that formed tower karst of the region is not mainly responsible for the accumulation of clastic sediment on the surface

X-ray standing wave study of the Sr/Si(001)-(2 x 3) surface, 2003, Goodner D. M. , Marasco D. L. , Escuadro A. A. , Cao L. , Tinkham B. P. , Bedzyk M. J. ,
Sub-monolayer surface phases of Sr on Si(0 0 1) have been studied with low-energy electron diffraction (LEED) and X-ray standing waves (XSW). A (3 x 1) phase was observed after depositing 0.6-0.8 ML Sr on room-temperature Si(0 0 1). Annealing at 750-800degreesC caused a portion of the Sr to desorb and resulted in a sharp (2 x 3) LEED pattern. Normal Si(0 0 4) and off-normal Si(0 2 2) and Si(1 11) XSW measurements made on the (2 x 3) phase indicate that Sr atoms must sit at either cave or bridge sites. The XSW results also suggest that if a sufficiently low anneal temperature is used. the (2 x 3) phase co-exists with short-range ordered regions of Sr atoms located at valley-bridge sites. (C) 2003 Elsevier B.V. All rights reserved

Results 1 to 15 of 44
You probably didn't submit anything to search for