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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 pokryty karst is (russian.) see covered karst.?

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

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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.
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

European Journal of Mineralogy, 2000, Vol 12, Issue 0, p. 1229-1243
Rare earth element anomalies in crandallite group minerals from the Schugorsk bauxite deposit, Timan, Russia
Abstract:
Crandallite group minerals from the Devonian bauxite deposit of Schugorsk, Timan, Russia, were studied by electron microprobe. Special attention was given to the distribution of the rare earth elements (REE). Of the A-site cations, essential are (oxides in wt.%) Ca (0.2 - 7.9), Sr (0.4 - 5.9), Ba (0.1 - 5.1), Pb (0.01 - 8.4), Y (to 2.4) and REE (to 21.6). Bi (A-site), Ga (B-site) and V (X-site) occur in trace amounts. Two main types of REE distribution in crandallite group minerals are distinguished. The first shows a clear negative Ce anomaly and partially depleted Pr; crandallite group minerals of this type formed under strong oxidising conditions (positive Eh and neutral to slightly alkaline pH values) and lost Ce due to its oxidation to Ce4 and accumulation in other minerals such as anatase. The second type displays a positive Sm anomaly and a negative Pr anomaly. Individual crandallite group crystals belonging to this type, I - 40 {micro}m in size, show a clear compositional zoning: the core is enriched in Ca, while the rim is enriched in S, Sr, Pb and the REE. This crandallite formed under reducing conditions related to stripping of Fe from the weathering profile. The presence of Sm2 in the crandallite lattice is proposed, and the role of organic material in its reduction is discussed. A Pr anomaly was inherited from the parent rock. A comparison of REE distribution in crandallite group minerals from different weathering profiles suggests that these minerals can be used to distinguish conditions of weathering