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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 antecedent precipitation index is a precipitation index that is based on the amount of previous precipitations [16].?

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


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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;
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Your search for preservation (Keyword) returned 81 results for the whole karstbase:
Showing 76 to 81 of 81
Unusual polygenetic void and cave development in dolomitized Miocene chalks on Barbados, West Indies, 2013,
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Sumrall J. B. , Mylroie J. E. , Machel H. G.

Barbados provides an unusual case of polygenetic cave development within dolomitized chalks and marls of the Miocene Oceanics Group. These diagenetic processes are driven by a succession and interplay of tectonic uplift, fracturing, hypogene fluid injection, overprinting by mixing zone diagenesis, and mechanical and biological erosion in the current littoral zone. The significance of the voids and caves within the chalks on Barbados are: 1) these appear to be the first dissolution caves documented in dolomitized chalk, and 2) these features show a polygenetic origin documenting the diagenetic changes in lithology that allowed the development and preservation of these cave types.


HYPOGENIC SPELEOGENESIS IN THE CRIMEAN FORE-MOUNTAINS (THE BLACK SEA REGION, SOUTH UKRAINE) AND ITS ROLE IN THE REGIONAL GEOMORPHOLOGY, 2013,
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Klimchouk A. , Amelichev G. , Tymokhina E. , Tokarev S.

 

The leading role in the geomorphic development of the Crimean fore-mountain region is played by the processes of dismemberment of “shielding” limestone layers of the monoclinal stratified structure through valley entrenchment, and by further retreat of vertical rocky outcrops via block-toppling mechanism. These processes are guided by the presense of hypogene karst structures, whose formation preceded the modern relief. Karstified fracture-karst zones, 100 to 400 m wide, in the Cretaceous-Paleogene strata controlled the entrenchment of valleys in the limestone layers. The basic elements of hypogenic karst structures, which form their spatial framework, are sub-vertical fracture-karst conduits (karst “rifts”). Denudational opening of vertical fracture-karst rift conduits in limestone layers set the cliff-like shape of valleys slopes, and presence of such rift conduits in the rear of cliffs of already incised valleys determines the block-toppling mechanisms of slope retreat. This maintains the verticality of cliff segments in the cuesta ridge and controls their position. Hypogenic sculptural morphology is extensively displayed in the exposed walls of cliffs (former conduit walls), which determines the originality and nomenclature of morphology of limestone cliffs of the Inner Ridge. In those areas of slopes where position of cliffs has stabilized for considerable time due to absence of new lines of block detachment in the rear, weathering becomes a significant process in the morphogenesis of surfaces. The abundance, outstanding expression, preservation and accessibility of relict hypogene karst features in the extensive cuesta cliffs of the Inner Ridge makes the region the foremost one for studying regularities of hypogene solution porosity development, the process currently ongoing in the adjacent artesian basin of the Plain Crimea.


MINE CAVES ON THE SOUTH-EASTERN FLANK OF THE HARZ MOUNTAINS (SAXONY-ANHALT, GERMANY) LE GROTTE DI MINIERA DEL VERSANTE SUD-ORIENTALE DELLE MONTAGNE DELLHARZ (SASSONIA-ANHALT, GERMANIA), 2013,
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Brust Michael K. , Nash Graham

The historical copper shale mine excavations on the south-eastern flank of Harz Mountains have cut into numerous large caves in gypsum and anhydrite. These caves are known as “Schlotten” (pl., sg. Schlotte). The word is derived from the Early New High German meaning internal hollow formations allowing the drainage of water and already finds mention in XVIth century literature. However, these quite spectacular gypsum caves have never aroused the interest of the wider public. Discovered through mining, they have always been only accessible via pit shafts and galleries and invariably considered to be part of the mine. But in a scientific sense they are deep phreatic and hypogene caves in a parent rock of anhydrite or gypsum, in their natural state filled with water and without an entrance. They are unique geological outcrops in Zechstein (upper Permian), large karst caves of rare character and particular beauty as well as cultural witnesses to historical mining. The miners used the “Schlotten” for a long period of time to drain water from the mines (until the XVIIIth century) and for economical reasons also to store unwanted spoil (until the XIXth century). As the mine workings reached deeper levels, sub- sidence and flooding became more common and the intensity of the karst dissolution process increased. Problems of catastrophic proportions due to mine flooding were encountered in 1892 near Eisleben and in 1988 near Sangerhausen. The hydrological problems that confronted the copper shale mine excavations in the south-eastern Harz region are of geogenic origin. The exploitable seams, which on average slope between 3º and 8º, are covered with a between 4 and 7 metre thick layer of limestone (Zechstein) with the characteristics of a karst aquifer. Above this a 60 m thick layer of anhydrite or gypsum is found, in which the “Schlotten” are formed, notably on geological faults. The relevance of the “Schlotten” as a natural phenomenon was first appreciated in depth by Johann Carl Freiesleben (1774-1846). He described them scientifically in 1809 and campaigned emphatically for their preservation. With regard to this, the “Wimmelburger Schlotten” near Eisleben were surveyed and geologically mapped by Anton Erdmann (1782-1848). The plan and side elevation of the cave survey were reproduced in copperplate and are considered to be the oldest published depiction of a gypsum cave in Germany. From the mid 70s the “Schlotten” became subject of speleological research for a short period of time. The abandoned projects have only recently been re-established. Two of the “Schlotten” are accessible via the Mining Museum Wettelrode: the “Segen-Gottes-Schlotte” and the “Elisabethschaechter Schlotte” near Sangerhausen. The “Wimmelburger Schlotten” near Eisleben are the largest gypsum caves in Germany and to a certain extent accessible for research.


BAHAMIAN CAVES AND BLUE HOLES: EXQUISITELY PRESERVED FOSSIL ASSEMBLAGES AND TAPHONOMIC INFLUENCES, 2014,
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Albury N. A. , Mylroie J. E.

In The Bahamas, caves and blue holes provide clues to the geologic and climatic history of archipelago but are now emerging as windows into the ecological and cultural past of islands. Cave environments in The Bahamas alternate cyclically between vadose and phreatic conditions with sea-level change, thereby providing unique but ephemeral fossil capture and preservation conditions.

A diverse assemblage of fossil plants and animals from Sawmill Sink, an inland blue hole on Abaco Island in the northern Bahamas, has revealed a prehistoric terrestrial ecosystem with exquisitely preserved fossil assemblages that result from an unusual depositional setting. The entrance is situated in the pine forest and opens into a flooded collapse chamber that intersects horizontal conduits at depths to 54 meters. The deepest passages are filled with sea water up to an anoxic mixing zone at depths of 14 to 9 meters and into the upper surface fresh-water layer. The collapse chamber is partially filled with a large talus pile that coincides with an anoxic halocline and direct sunlight for much of the day.

During glacioeustatic sea-level lowstands in the late Pleistocene, Sawmill Sink was a dry cave, providing roosting sites for bats and owls. Accumulations of bones deposited in depths of 25 to 30 meters were subsequently preserved by sea-level rise in the Holocene. The owl roost deposits are dominated by birds but also include numerous small vertebrate species that were actively transported by owls to the roost sites.

As sea levels rose in the Holocene, Sawmill Sink became a traditional passive pitfall trap. Significant quantities of surface derived organic material collected on the upper regions of the talus at the halocline where decaying plant material produced a dense layer of peat within an anoxic mixing zone enriched with hydrogen sulfide. Vertebrate species that drowned were entombed in the peat, where conditions inhibited large scavengers, microbial decomposition, and mechanical disarticulation, contributing to the superb preserva­tion of the fossil assemblage in the upper regions of the talus.


The Cova des Pas de Vallgornera (Llucmajor, Mallorca): a singular deposit bearing an exceptional well preserved Early Pleistocene vertebrate fauna, 2014,
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Bover P. , Valenzuela A. , Guerra C. , Rofes J. , Alcover J. A. Ginés J. , Fornós J. J. , Cuencabescós G. , Merino A.

The Cova des Pas de Vallgornera is the longest cave of Mallorca (Balearic Islands, Western Mediterranean) and one of the 30 longest caves in the world. The exploration of one of the galleries allowed the discovery of a fossiliferous deposit of vertebrate remains in a remarkable preservation state. The fossil faunal complex found in this gallery is composed of up to 5 mammalian species (Myotragus aff. kopperi, Hypnomys onicensis, Nesiotites aff. ponsi, Rhinolophus aff. mehelyi and Pipistrellus sp.), at least 14 bird species (among them two Mallorcan endemic taxa: Pica mourerae and Athene vallgornerensis), one reptile (Podarcis aff. lilfordi) and one amphibian (Discoglossus sp.). This faunal composition is similar to the one recorded in the Pedrera de s’Ònix, a well known deposit from the Early Pleistocene of Mallorca, and shared morphological characteristics between taxa of both deposits suggest that the chronology of the Cova des Pas de Vallgornera should be considered Early Pleistocene as well. Both taxonomical analysis and chronology of this fauna furnished information on some speleological aspects of the cave.


The fate of CO2 derived from thermochemical sulfate reduction (TSR) and effect of TSR on carbonate porosity and permeability, Sichuan Basin, China, 2015,
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Hao Fang, Zhang Xuefeng, Wang Cunwu, Li Pingping, Guo Tonglou, Zou Huayao, Zhu Yangming, Liu Jianzhang, Cai Zhongxian

This article discusses the role ofmethane in thermochemical sulfate reduction (TSR), the fate of TSR-derived CO2 and the effect of TSR on reservoir porosity and permeability, and the causes of the anomalously high porosity and permeability in the Lower Triassic soured carbonate gas reservoirs in the northeast Sichuan Basin, southwest China. The Lower Triassic carbonate reservoirs were buried to a depth of about 7000 m and experienced maximum temperatures up to 220 °C before having been uplifted to the present-day depths of 4800 to 5500 m, but they still possess porosities up to 28.9% and permeabilities up to 3360 md. The present-day dry gas reservoirs evolved from a paleo-oil accumulation and experienced varying degrees of TSR alteration as evidenced from the abundant sulfur-rich solid bitumens and varying H2S and CO2 concentrations. TSR occurred mainly within the oil and condensate/wet gas windows, with liquid hydrocarbons and wet hydrocarbon gases acting as the dominant reducing agents responsible for sulfate reduction, sulfur-rich solid bitumen and H2S generation, and calcite precipitation. Methane-dominated TSR was a rather late event and had played a less significant role in altering the reservoirs. Intensive H2S and CO2 generation during TSR resulted in calcite cementation rather than carbonate dissolution, which implies that the amount of water generated during TSR was volumetrically insignificant. 13C-depleted CO2 derived from hydrocarbon oxidation preferentially reacted with Ca2+ to form isotopically light calcite cements, and the remaining CO2 re-equilibrated with the 13C-enriched water–rock systems with its δ13C rapidly approaching the values for the host rocks, which accounted for the observed heavy and relatively constant CO2 δ13C values. The carbonate reservoirs suffered from differential porosity loss by TSR-involved solid bitumen generation and TSR-induced calcite and pyrite precipitation. Intensive TSR significantly reduced the porosity and permeability of the intervals expected to have relatively high sulfate contents (the evaporative-platform dolostones and the platform-margin shoal dolostones immediately underlying the evaporative facies). Early oil charge and limited intensity of TSR alteration, together with very low phyllosilicate content and early dolomitization, accounted for the preservation of anomalously high porosities in the reservoirs above the paleo-oil/water contact. A closed system seems to have played a special role in preserving the high porosity in the gas zone reservoirs below the paleo-oil/water contact. The closed system, which is unfavorable for deep burial carbonate dissolution and secondary porosity generation, was favorable for the preservation of early-formed porosity in deeply buried carbonates. Especially sucrosic and vuggy dolostones have a high potential to preserve such porosity.


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