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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 thixotropy is the property of a gel to become fluid under application of shear stresses [16].?

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.
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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;
See all featured articles from other geoscience journals

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Your search for desiccation (Keyword) returned 21 results for the whole karstbase:
Showing 16 to 21 of 21
Silicification of riphean carbonate sediments (Yurubcha-Tokhomo zone, Siberian Craton), 2005, Kuznetsov V. G. , Skobeleva N. M. ,
Types and lateral and vertical distribution of silicification in Riphean (largely dolomitic) rocks of the Yurubcha-Tokhomo zone of the Siberian Craton are discussed. It is shown that quartz and pyroclastic material in sediments were subjected to intense dissolution in a highly alkaline Riphean basin with the release of silica. Rapid and abrupt decrease in alkalinity during hiatus and desiccation periods resulted in the precipitation of dissolved silica and silicification of near-surface sediments. Lateral distribution of silicification was controlled by the redistribution of silica during the pre-Vendian hiatus, when surface waters were filtered through a carbonate massif with the simultaneous karst formation and silica dissolution. In the water discharge area, secondary silica was precipitated owing to changes in pH values and other physicochemical conditions

How much did climate force the Messinian salinity crisis? Quantified climatic conditions from pollen records in the Mediterranean region, 2006, Fauquette S, Suc Jp, Bertini A, Popescu Sm, Warny S, Bachiri Taoufiq N, Perez Villa Mj, Chikhi H, Feddi N, Subally D,
The latest Miocene (5.96 to 5.33[no-break space]Ma) is characterised by an outstanding event: the desiccation of the Mediterranean Sea (Messinian salinity crisis). It has been suggested that this was caused by a tectonic event, with no climatic change playing a role in desiccation. Quantifying the climate of the region during this period will help support or refute this hypothesis. An effective method for reconstructing the climate from Neogene pollen data is the 'Climatic Amplitude Method' based on the modern climatic requirements of plants to interpret fossil data. It has been conceived especially for periods devoid of modern vegetation analogue.Twenty Messinian to Lower Zanclean pollen sequences are now available in the peri-Mediterranean region. Most of them do not cover the whole Messinian interval, particularly those along the Mediterranean shorelines where sedimentation was interrupted during the sea's desiccation. In contrast, sedimentation was almost continuous in such areas as the Atlantic side of Morocco, along the Adriatic coast (including the Po Valley), and to a lesser extent the Black Sea. The Mediterranean sites nonetheless provide a reliable if not a discontinuous record of vegetation variability in time and space.A first examination of the pollen diagrams reveals a high regional variability controlled by local conditions, and throughout the interval a southward increase in herb pollen frequency in contrast to the tree pollen frequency. This indicates that open and probably dry environments existed in the southern Mediterranean region prior to, during and after the salinity crisis. Trees developed in areas close to mountains such as in the Po Valley, in Cerdanya and in the Black Sea region. Most variations observed in the pollen diagrams are constrained by fluctuations of Pinus pollen amounts, indicating eustatic variations. Climatic quantification from pollen data does not show obvious climatic changes due to the desiccation of the Mediterranean Sea, especially in the dry and warm southwestern Mediterranean area (Sicily, southern Spain and North Africa). At Maccarone, along the Adriatic Sea, a decrease in temperatures of the coldest month and, less importantly, a decrease in mean annual temperatures, corresponding to a drastic vegetation change, are reconstructed. These temperature variations are assumed to be controlled by regional environmental changes (massive arrival of waters in this basin) rather than to reflect cooling, because some authors link the second phase of evaporite deposition to a period of global warming. Some migrations of plants probably occurred as a response to Mediterranean desiccation. But the climatic contrast which has probably existed at that time between the central Mediterranean and the peripheral areas might be amplified.Climatic reconstruction from pollen data in the western Mediterranean area shows that climate is not the direct cause of the Mediterranean desiccation, as the Mediterranean region had experienced continuously high evaporation long before the crisis. Therefore the main factor leading to this event seems to be the successive closures of the Betic and Rifian corridors, isolating the Mediterranean Sea from the Atlantic Ocean

Exhumation of Messinian evaporites in the deep-sea and creation of deep anoxic brine-filled collapsed basins, 2006, Cita Mb,
The first part of the paper summarizes some basic concepts concerning (a) the distribution of Messinian evaporites in the deepest parts of the Mediterranean Sea and (b) the Mediterranean Ridge accretionary wedge and its peculiar characteristics deriving from the presence of a substantial evaporitic body in the deforming sedimentary prism.Then five brine-filled anoxic collapsed basins (Tyro, Bannock, Urania, Atalante and Discovery), discovered from 1983 to 1994, are presented and discussed in their physiographic, geologic, hydrologic and geochemical characters. High density brines deriving from submarine dissolution of outcropping or subcropping evaporites accumulate at the bottom of collapsed basins, if they are not swept away by submarine currents. The interface separating normal sea-water from high density brines is sharp with a density contrast of about 20% and lies at 3200-3500[no-break space]m below sea level. Strong bacterial activity is developing at the interface and living bacteria have been recovered from the anoxic salty brines. Thickness of the brines may be up to 500[no-break space]m. Thermal stratification has been observed in three brine lakes. Exhumation and dissolution of Messinian evaporites in the Mediterranean Ridge occur in different tectonic settings: pull-apart basin (Tyro), subducting seamount close to the outer deformation front (Bannock Basin), top of a backstop (Urania, Atalante and Discovery Basins).Chemistry of the brines is strongly variable and suggests dissolution of different layers or levels of the Messinian suite. Discovery brines are the saltiest ever recorded in natural environment. Their saturation in Mg chloride (bischofite), the end product of sea-water evaporation, suggests that the deepest parts of the eastern Mediterranean were close to dryness at the end of the salinity crisis, strongly supporting the deep basin desiccation model

Identifying Late Miocene episodes of connection and isolation in the Mediterranean-Paratethyan realm using Sr isotopes, 2006, Flecker R, Ellam Rm,
After decades of research, the timing and nature of Late Miocene connections between the Mediterranean, Paratethys and the global ocean are still speculative. The hydrologic flux implications of exchange or isolation are central to all hypotheses for generating the major lithological changes that represent the Messinian Salinity Crisis. Moreover, differences in the hydrologic fluxes envisaged are the primary distinction between models. Despite this, these fluxes remain largely unconstrained. This paper describes the basis for using Sr isotope data innovatively combined with salinity data through hydrologic budget modelling to determine the timing and nature of Mediterranean hydrologic connectivity. We examine the hypotheses for three Late Miocene events to illustrate how this approach allows us to test implied hydrologic scenarios and exclude incompatible models. 1) Pre-evaporite restriction of the Mediterranean; 2) the initiation of salt precipitation; 3) connection between the Sea of Marmara and both Paratethys and the Mediterranean during the Messinian. This process suggests that the Atlantic-Mediterranean exchange was significantly reduced up to three million years before evaporite precipitation. It also indicates that end-member hypotheses for initiating salt precipitation in the Mediterranean (desiccation and connected basin models) are inconsistent with Sr isotope data. A contrasting model where evaporite formation was triggered by Atlantic transgression into a strongly evaporation-dominated Mediterranean is shown to be more compatible with available datasets. The application to Sea of Marmara samples indicates that salinity changes in the basin were not caused by changes to the amount of inflow from either Paratethys or the Mediterranean. Other possible as yet untested applications important for constraining different aspects of the Messinian Salinity Crisis are highlighted

Present-day sedimentary facies in the coastal karst caves of Mallorca island (western Mediterranean), 2009, Forns J. J. , Gins J. , And Grcia F.
In spite of the increasing number of papers on cave sediments published during the last few decades, no one has focused from a sedimentological point of view on the processes that take place specifically within the coastal karst areas of carbonate islands. The objective of the present investigations is to deal with the sedimentary processes that take place inside two littoral caves of Mallorca (western Mediterranean), characterizing the different facies existing in the particular geological, geochemical, and hydrological setting that represents this very specific cave sedimentary environment. The recent exploration of extensive underwater galleries and chambers into some outstanding coastal caves of the island, has permitted the recognition of important accumulations of present-day sedimentary infillings in their drowned passages. Both the Pirata-Pont- Piqueta cave system and the Cova de sa Gleda have floors covered by muddy and/or sandy sediments which, in a wide sense, fit into two well-differentiated categories. On one hand we have allochthonous reddish mud sediments (mainly siliciclastic) and on the other hand autochthonous yellowish carbonate mud or sands. The mixing of both materials is also frequent as well as the accumulation of large blocks and debris due to the breakdown of roof and cave walls. A series of 21 manual cores was obtainedby scuba-divers in both caves, in order to collect the full thickness of sedimentary fill. Soil samples at the entrance of the two caves, as well as rock samples of the walls of both sites, were also obtained for a later comparison. Several sedimentary facies can be distinguished, which include coarse-grained deposits (entrance facies and breakdown blocks), fine-grained siliceous sediments (silts and muddy deposits with very variable organic matter content), carbonate deposits composed of calcite raft accumulations and/ or weathering-released limestone grains, and mixed facies including diverse proportions of the other sediment types. There are also some relict deposits composed of siliceous red silts, which are affected by polygonal desiccation cracks. In all the cases, the siliciclastic elements (quartz and feldspars, mainly) are related to rain events supplying dust of Saharan origin. The deposits and facies described herein correspond to different sedimentary environments that can be individualized inside the caves (collapse entrances, breakdown chambers, fully drowned passages and chambers, pools with free water surface), and reflect very specific hydrological, geochemical, and mechanical processes related to the coastal nature of the studied karst caves.

Distribution survey of Cyanobacteria in three Greek caves of Peloponnese, 2012, Lamprinou V. , Danielidis D. B. , Economouamilli A. , Pantazidou A.

Caves and hypogean environments host various phototrophic microorganisms, with Cyanobacteria constituting the major group. The spatial and temporal distribution of Cyanobacteria (156 taxa in total) from three Greek caves, located in the limestone arc of Peloponnese and differing in morphology, was studied. The community patterns in different ecological niches were analyzed in relation to environmental parameters (Photosynthetically Active Radiation, Temperature, and Relative Humidity). Cyanobacterial communities were found to thrive in patchy biofilms and showed known protective strategies against desiccation and irradiation. The nMDS analysis of the cumulative seasonal samples per sampling site showed no general pattern of distribution, with a clear differentiation of cyanobacterial communities among the three caves. Only in the typical cave ‘Kastria’, cyanobacterial taxa showed growth habits in accordance with the gradient of light from entrance inwards.

Results 16 to 21 of 21
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