MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 5
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 breathing hole is opening in the roof of a cave, cavern or other underground void through which air is sucked in and expelled in a rhythmic manner similar to inhalation and exhalation of breath [20]. related to blow hole and steam hole. synonyms: (french.) trou souffleur; (german.) luftloch, (greek.) anapneousa opi spileou; (spanish.) respirador; (turkish.) esintili delik.?

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

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 7
What is Karstbase?



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 mechanism (Keyword) returned 338 results for the whole karstbase:
Showing 16 to 30 of 338
Underground Streams on Acid Igneous Rocks in Victoria, 1981,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Finlayson, Brian

Underground streams occur in valley floors on acid igneous rocks over a wide area of eastern Victoria. In some cases the underground passage is capable of accommodating all streamflow levels so that there is no active surface channel. Three of them contain passages accessible to cavers. The literature contains very few references to features of this kind and there is some confusion as to whether they should be called 'pseudokarst'. Detailed descriptions and diagrams are presented for two of the sites, Labertouche and Brittania Creek. At North Maroondah, sinking streams on dacite have caused complications for hydrological experiments. Possible origins of these features are discussed and it is obvious that several mechanisms are feasible. One of the difficulties in determining modes of formation is that a variety of processes could lead to very similar end products. Three main theories on the mode of formation are suggested.

A possible mechanism for growth of calcite speleothems without participation of biogenic carbon dioxide, 1982,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Dreybrodt W,
Using Plummer et al.'s [11] rate equations on the dissolution and deposition of CaCO3 in H2O---CO2 systems, we have calculated deposition rates of CaCO3 to stalagmites in caves which are covered by glaciers or bare karst. In this case no biogenic CO2 from vegetated soil is available and the deposition of CaCO3 involves only atmospheric CO2. The mechanism of deposition proceeds by a temperature effect. Cold melting waters of about 0[deg]C dissolve CaCO3 under open system conditions at the surface of the rock. When this solution saturated with respect to CaCO3, flows through the limestone rock its temperature increases by several degrees. Therefore, it becomes supersaturated, and CaCO3 is deposited under open system conditions in the warmer cave. Maximal growth rates of about 10-3 cm/year are possible. From the kinetics of the deposition of CaCO3 from the thin water films present at the surface of stalagmites we are able to estimate the isotopic composition of carbon in the CaCO3 deposited on the stalagmites to be approximately [delta]13C = %, which is close to some observed values.From our data we conclude that substantial growth of stalagmites is possible during glacial periods as well as in areas of bare karst, a question which was not resolved up to now

Granite Caves in Girraween National Park, South-East Queensland, 1982,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Finlayson, Brian

Four caves and two underground streams in granite occur within the Girraween National Park. Only two of these sites have previously been reported. They mainly occur on the margins of major joints in the granite where streams descend into troughs along the joints. The caves are themselves formed in minor joints. In some cases streams have worked their way down from the surface along a joint but at three of the sites streams flow through horizontal joints in the granite which have not been opened from the surface. For these sites it is not clear how the initial passage was opened up underground. The two possible mechanisms suggested here are solution and joint opening following pressure release. The cave morphology clearly indicates that once the path flow is open, abrasion becomes the major process. Flowstone terraces, 'cave coral', and cemented gravels are found in the caves. The speleothems and the cement are amorphous silica (Opal A). Caves in granite may be more common than was previously thought.

Growth mechanisms of speleothems in Castleguard Cave, Columbia Icefields, Alberta, Canada, 1983,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Atkinson T. C.

Phases d'effondrements aux grottes prhistoriques, du Wrm l'Holocne dans le Midi de la France, 1985,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Blanc, J. J.
SEQUENCES OF COLLAPSES FROM WRM TO HOLOCENE IN PREHISTORIC CAVES (SOUTH-EAST OF FRANCE) - Multivariates methods (factorial and discriminant analysis) applied to many accurate stratigraphy and sedimentary sequences files deal just-dated cave-collapses observed into cavity and rock-shelters in the SE of France, show some detailed interpretations about the mechanism inducing the blocks-falls. This work places in a prominent position the various influences relative to cold climates and wet environments, degree of rock jointing of cave-walls and the sismo-tectonic impacts.

Time-Keeping Mechanisms and Their Ecological Significance in Cavernicolous Animals, 1985,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Lamprecht Gnther, Weber Friedrich

Shallow-marine carbonate facies and facies models, 1985,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Tucker M. E. ,
Shallow-marine carbonate sediments occur in three settings: platforms, shelves and ramps. The facies patterns and sequences in these settings are distinctive. However, one type of setting can develop into another through sedimentational or tectonic processes and, in the geologic record, intermediate cases are common. Five major depositional mechanisms affect carbonate sediments, giving predictable facies sequences: (1) tidal flat progradation, (2) shelf-marginal reef progradation, (3) vertical accretion of subtidal carbonates, (4) migration of carbonate sand bodies and (5) resedimentation processes, especially shoreface sands to deeper subtidal environments by storms and off-shelf transport by slumps, debris flows and turbidity currents. Carbonate platforms are regionally extensive environments of shallow subtidal and intertidal sedimentation. Storms are the most important source of energy, moving sediment on to shoreline tidal flats, reworking shoreface sands and transporting them into areas of deeper water. Progradation of tidal flats, producing shallowing upward sequences is the dominant depositional process on platforms. Two basic types of tidal flat are distinguished: an active type, typical of shorelines of low sediment production rates and high meteorologic tidal range, characterized by tidal channels which rework the flats producing grainstone lenses and beds and shell lags, and prominent storm layers; and a passive type in areas of lower meteorologic tidal range and higher sediment production rates, characterized by an absence of channel deposits, much fenestral and cryptalgal peloidal micrite, few storm layers and possibly extensive mixing-zone dolomite. Fluctuations in sea-level strongly affect platform sedimentation. Shelves are relatively narrow depositional environments, characterized by a distinct break of slope at the shelf margin. Reefs and carbonate sand bodies typify the turbulent shelf margin and give way to a shelf lagoon, bordered by tidal flats and/or a beach-barrier system along the shoreline. Marginal reef complexes show a fore-reef--reef core--back reef facies arrangement, where there were organisms capable of producing a solid framework. There have been seven such phases through the Phanerozoic. Reef mounds, equivalent to modern patch reefs, are very variable in faunal composition, size and shape. They occur at shelf margins, but also within shelf lagoons and on platforms and ramps. Four stages of development can be distinguished, from little-solid reef with much skeletal debris through to an evolved reef-lagoon-debris halo system. Shelf-marginal carbonate sand bodies consist of skeletal and oolite grainstones. Windward, leeward and tide-dominated shelf margins have different types of carbonate sand body, giving distinctive facies models. Ramps slope gently from intertidal to basinal depths, with no major change in gradient. Nearshore, inner ramp carbonate sands of beach-barrier-tidal delta complexes and subtidal shoals give way to muddy sands and sandy muds of the outer ramp. The major depositional processes are seaward progradation of the inner sand belt and storm transport of shoreface sand out to the deep ramp. Most shallow-marine carbonate facies are represented throughout the geologic record. However, variations do occur and these are most clearly seen in shelf-margin facies, through the evolutionary pattern of frame-building organisms causing the erratic development of barrier reef complexes. There have been significant variations in the mineralogy of carbonate skeletons, ooids and syn-sedimentary cements through time, reflecting fluctuations in seawater chemistry, but the effect of these is largely in terms of diagenesis rather than facies

Evidence for karstic mechanisms involved in the evolution the Moroccon hamadas., 1986,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Castellani Vittorio, Dragoni Walter
Underground tubular karst features, observed in an arid envinronment of southern Morocco, are described. On the basis of various evidences, it is suggested that such features were originated mainly by condensation water. A computation of the time necessary for their formation supports this hypothesis.

Le karst du massif des Calanques (Marseille Cassis), 1988,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Blanc J. J. , Monjeau R.
THE KARST OF THE CALANQUES massif - Description of karstic morphology in relation to lithology and tectonic framework; actual hydrography. Sedimentary analysis applied to speleothems (calcitic deposits, hardened silts with rubefaction, upper stalagmitic layers, eolianites). Relations with some recent tectonic mechanisms. Hydrogeology: marine resurgences, subterranean rivers (Port-Miou and Le Bestouan).

Pseudosinella revisited (Collembola, Entomobryinae), 1988,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Christiansen Kenneth, Moberg Thomas
Eight controversies are active in the study of macroevolution. These are: 1) the meaning of the term macroevolution, 2) the role of chance, 3) the role of stasis and gradualism, 4) whether significant change Is Iimited to speciation events, 5) the environmental conditions where macroevolutionary change occurs, 6) whether Neodarwinian mechanisms are adequate to explain change, 7) the existence and nature of hierarchical evolutonary processes, and 8) Darwin's views about all this. After a brief examination of each of these issues we used the extensive data available for 9 species of European and Nearctic cave Pseudosinella to examine the third, fourth and fifth controversies mentioned above. Our conclusions are that while we are unable to demonstrate ongoing directional selection, we have clear evidence that significant adaptive change is not limited to speciation events. It does however appear that the amount of adaptive change is greater in the process of speciation than in between. We also show that there is no evidence for clear periods of stasis in the evolution of these forms. This leads us to a new model of the macroevolutionary process combining features of gradualism and punctuated equilibrium. We also showed that evolutionary change Is not associated with unstable environments but rather with more stable ones.

An Investigation of the Mechanisms of Calcium Carbonate Precipitation on Straw Speleothems in Selected Karst Caves - Buchan, Victoria., 1988,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Canning, E.

The relative significance of straw speleothem growth from evaporation and from CO2 degassing was determined in Lilli-Pilli and Moons Caves (Buchan, Victoria) from a seven-month study of cave climate and water chemistry. The relative importance of these two mechanisms was inferred from the calculation of the straw growth rates according to a degassing model and an evaporation model. The modelled straw growth rates from the carbon dioxide degassing model were on hundred to one thousand times those attributable to evaporation. A third model was used to calculate straw growth rates from the overall supersaturation of the water. Growth rates were found to be within the range of 0.01 to 0.07mm per annum.

Comparative study of the kinetics and mechanisms of dissolution of carbonate minerals, 1989,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Chou L. , Garrels R. M. , Wollast R.

Land subsidence in the AI-Dahr residential area in Kuwait: a case history study, 1990,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Airifaiy Ia,
Four cylindrical sinkholes occurred between April 1988 and June 1989 in a residential area located 27 km south of Kuwait City. The physiographic and geological conditions of their development and the methods of survey followed to detect potential subsurface cavities in the area are discussed. The major sinkhole is 15 m in diameter and 31 m deep; the others are a few metres in size. A mechanism of migrating sinkholes is suggested, where the upper elastic sediments have been moved down into cavities of the underlying Dammam Limestone. Such movement could have been triggered by garden irrigation and urbanization. A conceptual model is introduced to explain the mechanism of this subsidence. Microgravity techniques were applied using a La Coste Model-D gravimeter to detect areas of subsurface weakness. Negative anomalies in the order of 80 microgals were recorded and considered to indicate underground cavities or zones of contrasted mass-deficiencies representing high risk areas. Moderate anomalies were also recorded and attributed to poor compaction of the ground prior to construction

Speciation of troglobites: studies in the San Antonio cave (Oaxaca, Mexico), 1991,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Junge Peter, Langecker Thomas G. , Wilkens Horst
The phylogenetically young species community of San Antonio Cave (Oaxaca, Mexico) exemplifies the hypothesis that speciation of troglobites can occur in close contact with epigean predecessors. In a subterranean creek which continues outside with a rich epigean fauna, four troglobitic aquatic crustacean and one fish species (Rhamdia reddelli, Pimelodidae) were studied. Today not a single surface specimen can be found in the cave waters although several epigean species are troglophilic and/or are the ancestors of cave forms in other parts of Mexico. The absence of epigean invaders is attributed to the presence of specimens of some of the more aggressive and carnivorous cave species close to the cave entrance. Contrary to this it can be presumed that at the beginning of the troglobitic evolution the cave ancestral epigean forms were regularly invading the cave. It is assumed that photonegative behaviour played a role for the initial colonization of the cave but it is not of significance as a separating mechanism for the speciation process.

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Marton P. , Rozloznik L. , Sasvari T. ,
The Silica nappe (s.l.) of the Inner West Carpathians consists of an essentially non-metamorphic, platform-type sedimentary complex of Mesozoic (chiefly Triassic) age. Palaeomagnetic samples were collected from 16 sites throughout the southern and northern Gemeric parts of this unit and from one site of the Mesozoic Meliata series which underlies the Silica nappe (s.s.) in south Gemer. The samples from each site were treated using thermal demagnetization and well-grouped magnetic directions of individual components were found for 13 (14) sites. Detailed analysis of the directional data showed (a) post-folding magnetization for four late Triassic-Jurassic sites in the eastern Slovak Karst, (b) synfolding magnetization for five sites in the western Slovak Karst with a direction corresponding to local palaeomagnetic data of African affinity for the late Cretaceous and (c) primary magnetizations in the northern Gemeric area for only two rock units with a declination difference which implies a relative rotation between these units. As all secondary remanences are of normal polarity it is very likely that their acquisition is related to the emplacement of the Silica nappe during the early late Cretaceous. The dominant remagnetization mechanism probably is CRM but occasional contributions of TVRM are also conceivable

Results 16 to 30 of 338
You probably didn't submit anything to search for