MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology


Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/template/toolbar_left.php 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 thermokarst is 1. a pitted periglacial or former periglacial surface in superficial deposits, produced by settling or caving of the ground after melting of ground ice [10]. 2. a term applied to topographic depressions in karstic terranes resulting from the thawing of ice. see cryokarst.?

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/speleogenesis.info/template/toolbar_right.php on line 7
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 oxygen (Keyword) returned 224 results for the whole karstbase:
Showing 166 to 180 of 224
Groundwater contamination in caves: four case studies in Spain, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Jimnezsnchez M. , Stoll H. , Vadillo I. , Lpezchicano M. , Domnguezcuesta M. , Martnrosales W. And Melndezasensio M.
Groundwater quality was monitored in four Spanish caves using concentrations of nitrate, potassium, phosphorus and in some cases total organic carbon. Three of the caves are located in NW Spain and contain prehistoric cave paintings and hence have special conservation interest. Of these, two are open show caves (Tito Bustillo and Pindal Caves), while the other one (Herreras Cave) is not managed for tours and is partially closed off to public access. The fourth cave (Las Maravillas Cave) is located in SW Spain and is opened to the public because of its geological features and natural beauty. In this paper, we compare two sampling methodologies used in the four caves. In Pindal and Herrerias Cave high temporal resolution is achieved with a dripwater collector that collects discrete samples every 48 hours. In Tito Bustillo and Las Maravillas Caves a higher spatial resolution is achieved (16 sampling points in each one), but with a frequency of sampling ranging from 15 days to 6 months. Wastewater and livestock waste appear to be the principal sources of contamination to cave waters. Caves with concentrated livestock (stables) or urban and residential wastewater systems directly situated above the cave exhibit the highest level of contamination detected in elevated concentrations of nitrogen species and in some cases depressed oxygen availability in waters

Monitoring climatological, hydrological and geochemical parameters in the Pre Nol cave (Belgium): implication for the interpretation of speleothem isotopic and geochemical time-series, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Verheyden S. , Genty D. , Deflandre G. , Quinif Y. And Keppens E.
Pre Nol cave climatology (air and water temperature, PCO2), hydrology (drip rate, conductivity) and geochemistry of water and calcite deposits (?18O, ?13C, Mg/Ca and Sr/Ca) where studied to better interpret stable isotopic and trace element variations of speleothems. Results of an automated monitoring station and of manual sampling between 1991 and 1998 have demonstrated the highly seasonal signal of drip rate, its control by water excess and rainfall, and, at a shorter scale to air pressure changes. The modern calcite deposit study suggests a relationship between cave calcite isotopic composition (?18O and ?13C) and drip rate likely due to variations in degree of isotopic equilibrium during calcite precipitation. ?18O and ?13C of the calcite are therefore, through drip rate, linked to water recharge. Mg/Ca and Sr/Ca ratios of Pre Nol cave calcite, depend closely on the residence time of the water, and therefore are also linked to drip rate and therefore to water recharge. This crossed link of ?18O and ?13C as of Mg/Ca and Sr/Ca to water recharge may explain the very similar variations of these four parameters along the longitudinal axis of a Holocene stalagmite, but it may also be the consequence of kinetic effects during calcite precipitation as suggested by similar variations of the four parameters along a single layer of the Holocene stalagmite.

Niche differentiation among sulfur-oxidizing bacterial populations in cave waters, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Jennifer L Macalady, Sharmishtha Dattagupta, Irene Schaperdoth, Daniel S Jones, Greg K Druschel And Danielle Eastman
The sulfidic Frasassi cave system affords a unique opportunity to investigate niche relationships among sulfur-oxidizing bacteria, including epsilonproteobacterial clades with no cultivated representatives. Oxygen and sulfide concentrations in the cave waters range over more than two orders of magnitude as a result of seasonally and spatially variable dilution of the sulfidic groundwater. A full-cycle rRNA approach was used to quantify dominant populations in biofilms collected in both diluted and undiluted zones. Sulfide concentration profiles within biofilms were obtained in situ using microelectrode voltammetry. Populations in rock-attached streamers depended on the sulfide/oxygen supply ratio of bulk water (r¼0.97; Po0.0001). Filamentous epsilonproteobacteria dominated at high sulfide to oxygen ratios (4150), whereas Thiothrix dominated at low ratios (o75). In contrast, Beggiatoa was the dominant group in biofilms at the sediment?water interface regardless of sulfide and oxygen concentrations or supply ratio. Our results highlight the versatility and ecological success of Beggiatoa in diffusion-controlled niches, and demonstrate that high sulfide/oxygen ratios in turbulent water are important for the growth of filamentous epsilonproteobacteria.

HYDROLOGIC CONNECTIONS AND DYNAMICS OF WATER MOVEMENT IN THE CLASSICAL KARST (KRAS) AQUIFER: EVIDENCE FROM FREQUENT CHEMICAL AND STABLE ISOTOPE SAMPLING, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Doctor, D. H.

A review of past research on the hydrogeology of the Classical Karst (Kras) region and new information obtained from a two- year study using environmental tracers are presented in this paper. The main problems addressed are 1) the sources of water to the Kras aquifer resurgence zone—including the famous Timavo springs—under changing flow regimes; 2) a quantification of the storage volumes of the karst massif corresponding to flow regimes defined by hydrograph recessions of the Timavo springs; and 3) changing dynamics between deep phreatic conduit flow and shallow phreatic and epiphreatic storage within the aquifer resurgence zone as determined through changes in chemical and isotopic composition at springs and wells. Particular focus was placed on addressing the long-standing question of the influence of the Soča River on the ground waters of the aquifer resurgence zone. The results indicate that the alluvial aquifer supplied by the sinking of the Soča River on the northwestern edge of the massif contributes approximately 75% of the mean annual outflow to the smaller springs of the aquifer resurgence zone, and as much as 53% to the mean annual outflow of the Timavo springs. As a whole, the Soča River is estimated to contribute 56% of the average outflow of the Kras aquifer resurgence. The proportions of Soča River water increase under drier conditions, and decrease under wetter conditions. Time series analysis of oxygen stable isotope records indicate that the transit time of Soča River water to the Timavo springs, Sardos spring, and well B-4 is on the order of 1-2 months, depending on hydrological conditions. The total baseflow storage of the Timavo springs is estimated to be 518 million m3, and represents 88.5% of the storage capacity estimated for all flow regimes of the springs. The ratio of baseflow storage volume to the average annual volume discharged at the Timavo springs is 0.54. The Reka River sinking in Slovenia supplies substantial allogenic recharge to the aquifer; however, its influence on the northwest resurgence zone is limited to the Timavo springs, and is only a significant component of the spring discharge under flood conditions for relatively brief periods (several days to weeks). Sustainability of the trans-boundary aquifer of the Kras will benefit from maintaining high water quality in the Soča River, as well as focused water tracing experiments within the epiphreatic zone of the aquifer to better delineate the recharge zone and to identify sources of potential contamination to the Brestovica water supply well.


Isotopic archives of sulphate in speleothems, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Wynn Peter M. , Fairchild Ian J. , Baker Andy, Baldini James U. L, Mcdermott Frank

The hemispheric impact of industrial emissions upon atmospheric sulphur loading is reflected in the sulphur depositional history recorded in cores from ice sheets. However, these do not reveal regional variations. Recently deposited speleothems are used here as archives of regional sulphur depositional history at two locations within the United Kingdom and Ireland. d34S-SO4 and d18O-SO4 present within speleothem carbonate are measured for the first time as part of a dual isotope approach to decode the speleothem sulphur record. The largely refractory nature of d34S-SO4 under oxidising conditions enables source provenance of atmospheric SO2, whereas the complex cycles of isotopic exchange and fractionation during incorporation of oxygen into sulphate molecules enable d18O-SO4 signatures to yield insights into ambient environmental conditions and biogeochemical cycling in the ecosystem above the cave. d34S-SO4 values extracted from speleothem carbonate formed within
Browns Folly Mine, UK, range from +3.5 to +5.5& and d18O-SO4 +10.3 to +13.7&. Both signatures lie within the range expected from sulphate deposition in industrial locations and reflect the transfer of sulphate into speleothem calcite with little fractionation. However, d18O-SO4 signatures at Crag Cave, western Ireland, are isotopically heavier than expected and approach isotopic equilibrium with d18O-H2O under reducing conditions. Dual isotope analysis of d34S-SO4 and d18O-SO4 optimises
the correct identification of sulphur sources and biogeochemical cycling prior to incorporation into the speleothem record. At carefully selected cave sites where drip water flowpaths into the cave remain oxic, speleothems hold the potential to retain records of atmospheric sulphur loading at the local and regional scale.


Groundwater contamination in caves: four case studies in Spain, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Jimnezsnchez M. , Stoll H. , Vadillo I. , Lpezchicano M. , Domnguezcuesta M. Martnrosales W. And Melndezasensio M.

Groundwater quality was monitored in four Spanish caves using concentrations of nitrate, potassium, phosphorus and in some cases total organic carbon. Three of the caves are located in NW Spain and contain prehistoric cave paintings and hence have special conservation interest. Of these, two are open show caves (Tito Bustillo and Pindal Caves), while the other one (Herrerías Cave) is not managed for tours and is partially closed off to public access. The fourth cave (Las Maravillas Cave) is located in SW Spain and is opened to the public because of its geological features and natural beauty. In this paper, we compare two sampling methodologies used in the four caves. In Pindal and Herrerias Cave high temporal resolution is achieved with a dripwater collector that collects discrete samples every 48 hours. In Tito Bustillo and Las Maravillas Caves a higher spatial resolution is achieved (16 sampling points in each one), but with a frequency of sampling ranging from 15 days to 6 months. Wastewater and livestock waste appear to be the principal sources of contamination to cave waters. Caves with concentrated livestock (stables) or urban and residential wastewater systems directly situated above the cave exhibit the highest level of contamination detected in elevated concentrations of nitrogen species and in some cases depressed oxygen availability in waters.


Monitoring climatological, hydrological and geochemical parameters in the Pre Nol cave (Belgium): implication for the interpretation of speleothem isotopic and geochemical time-series, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Verheyden S. , Genty D. , Deflandre G. , Quinif Y. , Keppens E.

Père Noël cave climatology (air and water temperature, PCO2), hydrology (drip rate, conductivity) and geochemistry of water and calcite deposits (δ18O, δ13C, Mg/Ca and Sr/Ca) where studied to better interpret stable isotopic and trace element variations of speleothems. Results of an automated monitoring station and of manual sampling between 1991 and 1998 have demonstrated the highly seasonal signal of drip rate, its control by water excess and rainfall, and, at a shorter scale to air pressure changes. The modern calcite deposit study suggests a relationship between cave calcite isotopic composition (δ18O and δ13C) and drip rate likely due to variations in degree of isotopic equilibrium during calcite precipitation. δ18O and δ13C of the calcite are therefore, through drip rate, linked to water recharge. Mg/Ca and Sr/Ca ratios of Père Noël cave calcite, depend closely on the residence time of the water, and therefore are also linked to drip rate and therefore to water recharge. This crossed link of δ18O and δ13C as of Mg/Ca and Sr/Ca to water recharge may explain the very similar variations of these four parameters along the longitudinal axis of a Holocene stalagmite, but it may also be the consequence of kinetic effects during calcite precipitation as suggested by similar variations of the four parameters along a single layer of the Holocene stalagmite.


Evolution of the isotopic composition of carbon and oxygen in a calcite precipitating H2OCO2CaCO3 solution and the related isotopic composition of calcite in stalagmites, 2008,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Dreybrod, W.

The isotopic composition of carbon and oxygen in a calcite precipitating CO2–H2O–CaCO3 solution is preserved in the calcite precipitated. For the interpretation of isotopic proxies from stalagmites knowledge of the evolution of δ13C and δ18O in the solution during precipitation is required. A system of differential equations is presented from which this evolution can be derived. Both, irreversible loss of carbon and oxygen from the solution with precipitation time τ and exchange of oxygen in the carbonates with the oxygen in the water with exchange time T are considered. For carbon, where no exchange is active, a modified equation of Rayleigh-distillation is found, which takes into account that precipitation stops at ceq, the saturation concentration of DIC with respect to calcite, and that ceq as well as the precipitation time τ is slightly different for the heavy and the light isotope. This, however, requires introducing a new parameter γ = (Aeq/Beq)/(A0/B0), which has to be determined experimentally. (Aeq/Beq) is the isotopic ratio for the heavy (A) and the light isotope (B) at both chemical and isotopic equilibrium and (A0/B0) is the initial isotopic ratio of the solution. In the case of oxygen, where exchange is present, the isotopic shifts are reduced with increasing values of the precipitation time τ. For τ ≫ T the solution stays in isotopic equilibrium with the oxygen in the water during the entire time in which precipitation is active. The isotopic ratios in a calcite precipitating solution R(t)/R0 = (1 + δ(t)/1000) for carbon are plotted versus those of oxygen. R0 is the isotopic ratio at time t = 0, when precipitation starts and δ(t) the isotopic shift in the solution after time t. These show positive correlations for the first 50% of calcite, which can precipitate. Their slopes increase with increasing values of τ and they closely resemble Hendy-tests performed along growth layers of stalagmites. Our results show that stalagmites, which grow by high supply of water with drip times less than 50 s, exhibit positive correlations between δ13C and δ18O along a growth layer. But in spite of this the isotopic composition of oxygen in the solution at the apex is in isotopic equilibrium with the oxygen in the water, and therefore also that of calcite deposited at the apex.


The legend of carbon dioxide heaviness, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Badino G.
The false legend of carbon dioxide traps resulting from the weight of carbon dioxide gas is disproved. In spite of water-vapor lightness in comparison with air, no water-vapor trap exists on cave ceilings. In fact, underground atmospheres with specific compositions are not related to gravity, but to the absence of any air movement around the gas sources. The process of double diffusion of oxygen and carbon dioxide during organic compound decomposition in still air is shown to be significant. This phenomenon can form atmospheres that are deadly due to oxygen deficiencies and poisonous because of excess carbon dioxide. Carbon dioxide storage behaves like a liquid and can flow or can be poured, as cold air can, but these are typical transient processes with no relation to a caves foul air formation.

Limitations of hendy test criteria in judging the paleoclimatic suitability of speleothems and the need for replication, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Dorale J. A. And Liu Z.
Carbon and oxygen isotopes in calcite speleothems are powerful proxies for understanding past climate change. For calcite deposited under isotopic equilibrium conditions, variations in d18 O values directly reflect changes in cave temperature and the isotopic composition of meteoric water. Speleothem d13 C values have bedrock, atmospheric, and soil gas sources. Soil gases can be traced to the overlying vegetation, which is related to climate. Both d13 C and d18 O values are therefore potentially powerful tracers of climate change. Processes that could alter speleothem d13 C and/or d18 O values, and thereby mask primary environmental signals, fall in the categories of 1) kinetic processes, including deposition of calcite out of isotopic equilibrium, and 2) vadose processes, including evaporation of water at or near the land surface. In truth, there is no absolute test for the absence of these kinetic/vadose-zone processes. However, the Hendy Test is widely used for assessing whether isotopic equilibrium existed during the time of calcite deposition. Criterion (1) of the Hendy Test (i.e., that d18 O values remain constant along a single growth layer) may not be a valid control of equilibrium conditions because isotopic equilibrium could theoretically occur in the center of the speleothem at the same time that kinetic fractionation occurs at the flanks. Moreover, the concept of sampling along a single growth layer is flawed in both theory and practice. Criterion (2) of the Hendy Test (i.e., that there is no relationship between d13 C and d18 O) is based on the assumption that speleothem d13 C values are not linked to climate. However, speleothem d13 C values may well be linked to climate because climate provides a first-order control on soil productivity and the type of vegetation. Therefore, Hendy Test criterion (2) is not a prerequisite to isotopic equilibrium in all cases. We propose instead the Replication Test (i.e., the demonstration of similar isotopic profiles among two or more speleothems) for evaluating the likelihood of calcite deposition under isotopic equilibrium conditions. Replication of isotopic profiles among two or more speleothems is possible only if kinetic/vadose-zone processes are either: 1) absent or 2) have affected spatially separated speleothems in exactly the same way. Because the second scenario is highly unlikely, we propose that the Replication Test is effectively sufficient in ruling out kinetic/vadose- zone overprinting processes. We further suggest that the Replication Test is far more robust in testing for the absence of the wide range of processes described above than is the traditional Hendy Test.

Cryogenic cave carbonates from the Cold Wind Cave, Nzke Tatry Mountains, Slovakia: Extending the age range of cryogenic cave carbonate formation to the Saalian, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
k K. , Hercman H. , Orvoov M. , Ja?kov I.
Cold Wind Cave, located at elevations ranging between 1,600 and 1,700 m a. s. l. in the main range of the Nzke Tatry Mountains (Slovakia), is linked in origin with the adjacent Dead Bats Cave. Together, these caves form a major cave system located within a narrow tectonic slice of Triassic sediments. Both caves have undergone complex multiphase development. A system of sub-horizontal cave levels characterized by large, tunnel-like corridors was formed during the Tertiary, when elevation differences surrounding the cave were less pronounced than today. The central part of the Nzke Tatry Mountains, together with the cave systems, was uplifted during the Neogene and Lower Pleistocene, which changed the drainage pattern of the area completely. The formation of numerous steep-sloped vadose channels and widespread cave roof frost shattering characterized cave development throughout the Quaternary. In the Cold Wind Cave, extensive accumulations of loose, morphologically variable crystal aggregates of secondary cave carbonate ranging in size between less than 1 mm to about 35 mm was found on the surface of fallen limestone blocks. Based on the C and O stable isotope compositions of the carbonate (?13C: 0.72 to 6.34 , ?18O: 22.61 to 13.68 V-PDB) and the negative relation between ?13C and ?18O, the carbonate crystal aggregates are interpreted as being cryogenic cave carbonate (CCC). Published models suggest the formation of CCC in slowly freezing water pools, probably on the surface of cave ice, most probably during transitions from stadials to interstadials. Though the formation of these carbonates is likely one of the youngest events in the sequence of formation of cave sediments of the studied caves, the 230Th/234U ages of three samples (79.72.3, 104.02.9, and 180.06.3 ka) are the oldest so far obtained for CCC in Central Europe. This is the first description of CCC formation in one cave during two glacial periods (Saalian and Weichselian).

IDENTIFYING PALEO WATER-ROCK INTERACTION DURING HYDROTHERMAL KARSTIFICATION: A STABLE ISOTOPE APPROACH, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Dublyansky Y. , Spotl C.

Haloes of altered oxygen isotope values ranging in size from < 1 m to several km have been reported around hydrothermal ore deposits. We have found that similar alteration zones could be induced by lukewarm to thermal cave-forming waters. A paleo wall in Entrische Kirche cave (Gastein Valley, Austrian Alps) preserved a 5 cm-thick brownish zone behind a thick flowstone. Across this zone the O isotope values gradually increase by 11 ‰, until they reach values characteristic of the unaltered marble. The isotope composition in the alteration zone is very different from that of the ?owstone above but is similar to phreatic calcite spar from hypogene (thermal) karst cavities in surface outcrops in the area. We interpret this isotopic pro?le as re?ection of the water-rock interaction in a low-temperature hydrothermal karst system. Similar alteration pro?les were found around solutional cavities at Hllenstein (Tux Valley, Austrian Alps), lined with hydrothermal calcite. Sigmoid shapes of isotope profiles suggest that the most-altered bedrock was isotopically equilibrated with paleo waters. This allows use of isotope mass-balance calculations to assess the temperature of the paleo waters. Isotope profiles acquired from a number of other hypogene caves in Austria failed to show any isotopic signals of bedrock alteration.


HYPOGENE CAVES IN THE APENNINES (ITALY), 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Galdenzi S.

In the Apennine Mountains many examples of hypogene caves are known, generally related to present or past rise of sulfidic water that, mixing with oxygenated water of shallow flow systems, causes the sulfuric acid dissolution of limestone. The hypogene caves are generally located in small limestone outcrops covered by rocks of low permeability that in?uence the groundwater flowpaths. Some caves, however, are known also in hydrogeological massifs, where epigenic caves prevail. The hypogene caves show different patterns, ranging from phreatic to pure water table caves. The former prevail when karst evolved below the water table in structures almost completely covered by low permeability units; the latter occur in zones where a fast recharge of freshwater can reach the sulfidic water from the karst surface. The progressive lowering, thinning and removal of the low-permeability covers by non-karstic erosion processes can cause the progressive evolution from phreatic to water table caves. Active speleogenetic processes due to H2 S oxidation can be directly observed in different hydrogeologic settings: in highly permeable aquifers with ready recharge of freshwater (Frasassi caves), in thermal caves, below low permeability cover (Acquasanta Terme), or in marine thermal caves with salt water intrusion (Capo Palinuro).


HYDROTHERMAL ORIGIN OF ZADLAKA JAMA, AN ANCIENT ALPINE CAVE IN THE JULIAN ALPS, SLOVENIA, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Knez M. , Slabe T.

Zadlaka Jama was formed in an aquifer below the water table level as a dense network along bedding planes and fractures. It is an anastomosing network system of horizontal and vertical tubes. A selection of tubes grew into larger passages. In addition to the speci?c fracture controls, did hydrothermal water flooding the cave from below, contribute to the development of its dense network of passages? PALMER (1995) observes that when water rich in sulphur mixes with water rich in oxygen in zones of fractured rock, initial cave networks develops. Water from the spring below Zadlaka Jama (Figure 1) has a high carbonate and potassium content and total hardness (400 mg/l); chlorides are somewhat higher in the content as is the proportion of sulphates (40 mg/l). DUBLYANSKY (1989) found that water less than 20o C – in this cave temperature of water is 20.7o C - does not cause distinct development of hydrothermal karst, although mixing of waters with different characteristics and temperatures frequently can cause the development of network maze cave systems (DUBLYANSKY, 1997). FORTI (1996) describes the formation of a three-dimensional cave system that was the consequence of mixing thermal water at a declining water table level with percolating water from the surface. At Zadlaka Jama such a mode of cave formation can only be attributed to its early stages, while all other forms are those of varying fast water flows and of filling of the cave with fine grained sediment.


U-series dating and isotope geochemical study of the Gellrt Hill (Budapest) travertine, 2009,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/speleogenesis.info/include/functions1.php on line 943
Kele S. , Scheuer G. , Demny A. , Shen Ch. C. , Chiang H. W.

Travertine is quite a common formation in the area of Budapest (Hungary) indicating strong hydrothermal activity during the Pliocene and Quaternary. It covers former terraces of the Danube River and older geomorphologic horizons; thus, it is an important archive to date fluvial terraces and tectonic movements. Despite numerous investigations performed on these deposits, only few radiometric data are available so far and the absence of the exact timing information hindered paleoclimatic interpretation. The area of Gellért Hill consists mainly of Upper Triassic dolomite, but Quaternary travertine can also be found. In this study a detailed petrographic and stable isotope geochemical study of four travertine sites (1. Ifjúsági Park; 2. Számadó u. (Street); 3. Kelenhegyi u. (Street); 4. Somlói u. (Street)) of the Gellért Hill area is presented, along with analyses on the recent carbonate deposits of Gellért Hill and Sárosfürdõ. The travertine of Ifjúsági Park and Számadó u. are spring cone deposits, while the travertine of the Kelenhegyi u. represents a shallow-water depositional environment. based on the paleontological studies of Jánossy (in Scheuer and Schweitzer, 1988) the Gellért Hill travertine was thought to have been formed during the Lower Pleistocene; however, no radiometric age dating had been performed on these deposits prior our study. Our U/Th analyses yielded ages of 250±44 ky for the Ifjúsági Park travertine (220 m asl) and 180±49 ky for the Számadó u. travertine (195 m asl). These new U/Th ages are in contradiction with the previously assumed Lower Pleistocene age, implying gradual relative decrease in the paleokarst water-level and proving that the elevation of the individual travertine deposits not necessarily show their relative age. The uplift rates of Gellért Hill calculated from the U/Th age data and elevation of travertine occurrences range between 0.47 and 0.52 mm/yr, which is significantly higher than the uplift rates calculated for the Rózsadomb area (0.20 0.25 mm/yr; Kele et al., submitted). The difference in the incision rates between the individual sub-areas suggests that selective uplift was characteristic for the Buda Hills during the Middle Pleistocene; thus, up-scaling reconstruction of paleokarst waterlevel for the whole area from a given locality is not possible. Oxygen isotope analyses of recent carbonate deposits of Gellért Hill, Sárosfürdõ and Rudas Spa revealed that these calcites precipitated under non-equilibrium conditions, and the measured calcitewater oxygen isotope fractionation show the same positive shift relative to "equilibrium values" as was observed in the case of the recently-forming Egerszalók travertine (Kele et al. 2008). Assuming that the water of the paleo-springs of Gellért Hill derived from precipitation infiltrated during interstadial periods of the Pleistocene and considering non-equilibrium deposition (i.e. using the empirical calcite-water oxygen isotope fractionation of Kele et al. 2008), their calculated paleotemperature could range between 22 (±4) °C and 49 (±6) °C. based on the 18Otravertine differences the Ifjúsági Park and the Számadó u. spring cone type travertine was deposited from the highest temperature water, while from the lowest temperature water the travertine of Kelenhegyi u. was formed.


Results 166 to 180 of 224
You probably didn't submit anything to search for