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 cleavage is the tendency to cleave or split along definite parallel planes, which may be highly inclined to the bedding. it is a secondary structure and is ordinarily accompanied by at least some recrystallinization of the rock.?

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

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 hypogene (Keyword) returned 276 results for the whole karstbase:
Showing 31 to 45 of 276
Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs, 2006, Toth D. J. , Katz B. G.

Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca–HCO3 (six), Na–Cl (four), and mixed (one). The evolution of water chemistry for Ca– HCO3 spring waters was modeled by reactions of rainwater with soil organic matter, calcite, and dolomite under oxic conditions. The Na–Cl and mixed-type springs were modeled by reactions of either rainwater or Upper Floridan aquiferwater with soil organic matter, calcite, and dolomite under oxic conditions and mixed with varying proportions of saline Lower Floridan aquifer water, which represented 4–53% of the total spring discharge. Multiple-tracer data—chlorofluorocarbon CFC-113, tritium (3H), helium- 3 (3Hetrit), sulfur hexafluoride (SF6)—for four Ca–HCO3 spring waters were consistent with binary mixing curves representing water recharged during 1980 or 1990 mixing with an older (recharged before 1940) tracer-free component. Young-water mixing fractions ranged from 0.3 to 0.7. Tracer concentration data for two Na–Cl spring waters appear to be consistent with binary mixtures of 1990 water with older water recharged in 1965 or 1975. Nitrate-N concentrations are inversely related to apparent ages of spring waters, which indicated that elevated nitrate-N concentrations were likely contributed from recent recharge.

Structurally controlled hydrothermal alteration of carbonate reservoirs: Introduction, 2006, Smith L. B. Jr. , Davies G. R.

Structurally controlled hydrothermal dolomite reservoir facies: An overview, 2006, Davies G. R. , Smith Jr. L. B.

Structurally controlled hydrothermal dolomite (HTD) reservoir facies and associated productive leached limestones are major hydrocarbon producers in North America and are receiving increased exploration attention globally. They include multiple trends in the Ordovician (locally, Silurian and Devonian) of the Michigan, Appalachian, and other basins of eastern Canada and the United States, and in the Devonian and Mississippian of the Western Canada sedimentary basin. They also occur in Jurassic hosts along rifted Atlantic margins, in the Jurassic–Cretaceous of the Arabian Gulf region and elsewhere. Hydrothermal dolomitization is defined as dolomitization occurring under burial conditions, commonly at shallow depths, by fluids (typically very saline) with temperature and pressure (T and P) higher than the ambient T and P of the host formation. The latter commonly is limestone. Proof of a hydrothermal origin for HTD reservoir facies requires integration of burial-thermal history plots, fluidinclusion temperature data, and constraints on timing of emplacement. Hydrothermal dolomite reservoir facies are part of a spectrum of hydrothermal mineral deposits that include sedimentary-exhalative lead-zinc ore bodies and HTD-hostedMississippi Valley–type sulfide deposits. All three hydrothermal deposits show a strong structural control by extensional and/or strike-slip (wrench) faults, with fluid flowtypically focused at transtensional and dilational structural sites and in the hanging wall. Transtensional sags above negative flower structures on wrench faults are favored drilling sites for HTD reservoir facies. Saddle dolomite in both replacive and void-fillingmodes is characteristic of HTD facies. For many reservoirs, matrix-replacive dolomite and saddle dolomite appear to have formed near-contemporaneously and from the same fluid and temperature conditions. The original host facies exerts a major influence on the lateral extent of dolomitization, resultant textures, pore type, and pore volume. Breccias zebra fabrics, shear microfractures, and other rock characteristics record short-term shear stress and pore-fluid-pressure transients, particularly proximal to active faults. High-temperature hydrothermal pulses may alter kerogen in host limestones, a process designated ‘‘forced maturation.’’ basement highs, underlying sandstone (and/ or carbonate?) aquifers (probably overpressured), and overlying and internal shale seals and aquitards also may constrain or influence HTD emplacement. Although many questions and uncertainties remain, particularly in terms of Mg and brine source and mass balance, recognition and active exploration of the HTD play continues to expand. Increasing use of three-dimensional seismic imagery and seismic anomaly mapping, combined with horizontal drilling oblique to linear trends defined by structural sags, helps to reduce risk 

Evidence against the Dorag (mixing-zone) model for dolomitization along the Wisconsin arch - A case for hydrothermal diagenesis , 2006, Luczaj, J. A.

Ordovician carbonates near the Wisconsin arch represent the type locality in ancient rocks for the Dorag, or mixing-zone, model for dolomitization. Field, petrographic, and geochemical evidence suggests a genetic link between the pervasive dolomite, trace Mississippi Valley–type (MVT) minerals, and potassium (K)-silicate minerals in these rocks, which preserve a regional hydrothermal signature. Constraints were placed on the conditions of water-rock interaction using fluid-inclusion methods, cathodoluminescence and plane-light petrography, stable isotopic analyses, and organic maturity data. Homogenization temperatures of two-phase aqueous fluid inclusions in dolomite, sphalerite, and quartz range between 65 and 120°C. Freezing data suggest a Na-Ca-Mg-Cl-H2O fluid with salinities between 13 and 28 wt.% NaCl equivalent. The pervasive dolomitization of Paleozoic rocks on and adjacent to the Wisconsin arch was the result of water-rock interaction with dense brines at elevated temperatures, and it was coeval with regional trace MVT mineralization and K-silicate diagenesis. A reevaluation of the Dorag (mixing-zone) model for dolomitization, in conjunction with convincing new petrographic and geochemical evidence, has ruled out the Dorag model as the process responsible for pervasive dolomitization along the Wisconsin arch and adds to the abundant body of literature that casts serious doubt about the viability of the Dorag model in general.

John Luczaj is an assistant professor of earth science in the Department of Natural and Applied Sciences at the University of Wisconsin–Green Bay. He earned his B. S. degree in geology from the University of Wisconsin–Oshkosh. This was followed by an M.S. degree in geology from the University of Kansas. He holds a Ph.D. in geology from Johns Hopkins University in Baltimore, Maryland. His recent interests include the investigation of water-rock interaction in Paleozoic sedimentary rocks in the Michigan Basin and eastern Wisconsin. Previous research activities involve mapping subsurface uranium distributions, reflux dolomitization, and U-Pb dating of Permian Chase Group carbonates in southwestern Kansas.

Pervasive dolomitization with subsequent hydrothermal alteration in the Clarke Lake gas field, Middle Devonian Slave Point Formation, British Columbia, Canada , 2006, Lonnee J. , Machel H. G.

The Clarke Lake gas field in British Columbia, Canada, is hosted in pervasively dolomitized Middle Devonian carbonates of the Slave Point Formation. The Clarke Lake field consists mostly of pervasive matrix dolomite and some saddle dolomite, the latter varying in volume from about zero in limestones to normally 20–40% (locally up to 80%) in dolostones over any given 10-m (33-ft) core interval. Some of the saddle dolomite is replacive, some is cement, and both varieties are associated with dissolution porosity and recrystallized matrix dolomite. The major objective of this study is to identify the causes and timing of matrix and saddle dolomite formation, specifically, whether these dolomites are hydrothermal. A comprehensive petrographic and geochemical examination indicates that pervasive matrix dolomitization was accomplished by long-distance migration of halite-saturated brines during the Late Devonian toMississippian. Fluid-inclusion homogenization temperatures suggest about 150 (uncorrected) to 190jC (corrected) at the time of matrix dolomitization. These temperatures differ markedly from most published work on the dolomitized Devonian reefs in the Alberta Basin south of the Peace River arch, where pervasive matrix dolomitization was accomplished by advection of slightly modified seawater at temperatures of about 60–80jC, and where no hydrothermal influence was ever present. The saddle dolomites at Clarke Lake are not cogenetic with matrix dolomite and are not the product of hydrothermal dolomitization (sensu stricto). Instead, they formed through the hydrothermal alteration of matrix dolomite by way of invasion of a gypsum-saturated brine during periods of extremely high heat flow and regional plate-margin tectonics in the Late Devonian to Mississippian. Fluidinclusion homogenization temperatures suggest that hydrothermal alteration occurred between 230 (uncorrected) and 267jC (corrected), which is significantly higher than the maximumtemperature of about 190jC attained by the Slave Point Formation during burial. The sources of the halite- and gypsum-saturated brines are Middle Devonian evaporite depositional environments roughly 200 km (124 mi) south and/or east of Clarke Lake, near the Peace River arch

Three-dimensional seismic-based definition of fault-related porosity development: TrentonBlack River interval, Saybrook, Ohio, 2006, Sagan J. A. , Hart B. S.

Oil and gas reservoirs of the Ordovician Trenton–Black River interval in the Appalachian Basin are commonly associated with fault-related hydrothermal dolomites. However, relationships between porosity development and fault geometry in these fields are poorly documented. In this article, we integrate three-dimensional (3-D) seismic and wire-line data from the Trenton–Black River interval at Saybrook field in northeastern Ohio to study relationships between faulting and porosity development there. Faults were mapped using a combination of amplitude and coherency versions of the seismic data, and a 3-D porosity volume was generated for the Trenton–Black River interval by integrating attributes derived from the seismic data with log-based measures of porosity.

The productive trend in the Trenton–Black River interval at Saybrook is controlled by a 3.4-mi (5.5-km)-long, northwest-southeast–oriented basement fault that was probably reactivated during the Taconic orogeny (i.e., Late Ordovician). Strike-slip movement along the fault generated en echelon synthetic shear faults that branch at least 1350 ft (411.5 m) upward into the Trenton–Black River interval. The best porosity is developed in areas between overlapping synthetic shear faults. Antithetic shear faults probably formed at these locations and, when combined with minor dip-slip movement, created conduits for subsequent porosity-generating fluids. Circular collapse structures associated with localized extension between overlapping shear faults are the primary drilling targets, and horizontal wells running parallel to the strike of the fault would have the best chances of intercepting good porosity development.

Justine Sagan obtained her B.Sc. and M.Sc. degrees in the Earth and Planetary Sciences Department at McGill University. The work presented in this article is based on her M.Sc. thesis. She is currently employed by Devon Canada Corporation in Calgary.

 Bruce Hart held positions with the Geological Survey of Canada, Pennsylvania State University, and the New Mexico Bureau of Mines and Mineral Resources prior to joining McGill University in 2000. His research focuses on the integration of three-dimensional seismic and other data types for reservoir characterization programs. He has been an associate editor of the AAPG

Fractured hydrothermal dolomite reservoirs in the Devonian Dundee Formation of the central Michigan Basin, 2006, Luczaj J. A. , Harrison Iii. W. B. , Williams N. S.

The Middle Devonian Dundee Formation is the most prolific oilproducing unit in the Michigan Basin, with more than 375 million bbl of oil produced to date. Reservoir types in the Dundee Formation can be fracture controlled or facies controlled, and each type may have been diagenetically modified. Although fracture-controlled reservoirs produce more oil than facies-controlled reservoirs, little is known about the process by which they were formed and diagenetically modified. In parts of the Dundee, preexisting sedimentary fabrics have been strongly overprinted by medium- to coarse-grained dolomite. Dolomitized intervals contain planar and saddle dolomite, with minor calcite, anhydrite, pyrite, and uncommon fluorite. Fluid inclusion analyses of two-phase aqueous inclusions in dolomite and calcite suggest that some water-rock interaction in these rocks occurred at temperatures as high as 120–150jC in the presence of dense Na-Ca-Mg-Cl brines. These data, in conjunction with published organic maturity data and burial reconstructions, are not easily explained by a long-term burial model and have important implications for the thermal history of the Michigan Basin. The data are best explained by a model involving short-duration transport of fluids and heat from deeper parts of the basin along major fault and fracture zones connected to structures in the Precambrian basement. These data give new insight into the hydrothermal processes responsible for the formation of these reservoirs. 

Tectonic-hydrothermal brecciation associated with calcite precipitation and permeability destruction in Mississippian carbonate reservoirs, Montana and Wyoming , 2006, Katz D. A. , Eberli G. P. , Swart P. K. , Smith Jr. L. B.

The Mississippian Madison Formation contains abundant fracture zones and breccias that are hydrothermal in origin based on their morphology, distribution, and geochemical signature. The hydrothermal activity is related to crustal shortening during the Laramide orogeny. Brecciation is accompanied by dedolomitization, late-stage calcite precipitation, and porosity occlusion, especially in outcrop dolomites. The tectonic-hydrothermal late-stage calcite reduces permeability in outcrops and, potentially, high-quality subsurface reservoir rocks of the subsurface Madison Formation, Bighorn Basin. The reduction of permeability and porosity is increased along the margins of the Bighorn Basin but not predictable at outcrop scale. The destruction of porosity and permeability by hydrothermal activity in the Madison Formation is unique in comparison to studies that document enhanced porosity and permeability and invoke hydrothermal dolomitization models. Hydrothermal breccias from the Owl Creek thrust sheet are classified into four categories based on fracture density, calcite volume, and clast orientation. Shattered breccias dominate the leading edge of the tip of the Owl Creek thrust sheet in the eastern Owl Creek Mountains, where tectonic deformation is greatest, whereas fracture, mosaic, and chaotic breccias occur throughout the Bighorn Basin. The breccias are healed by calcite cements with d18O values ranging between _26.5 and _15.1xPeedee belemnite (PDB), indicating that the cements were derived from isotopically depleted fluids with elevated temperatures. In the chaotic and mosaic breccia types, large rotated and angular clasts of the host rock float in the matrix of coarse and nonzoned late-stage calcite. This appearance, combined with similar d18O values across even large calcite veins, indicates that the calcite precipitated rapidly after brecciation. Values for d13C(_5–12xPDB) from the frontal part of the Owl Creek thrust sheet indicate equilibrium between methane and CO2-bearing fluids at about 180jC. Fluid inclusions from the eastern basin margin show that these cements are in equilibrium with fluids having minimum temperatures between 120 and 140jC and formed from relatively low-salinity fluids, less than 5 wt.% NaCl. Strontium isotope ratios of these hydrothermal fluids are more radiogenic than proposed values for Mississippian seawater, suggesting that the fluids mixed with felsic-rich basement before migrating vertically into the Madison Formation. We envisage that the tectonic-hydrothermal late-stage calcitecemented breccias and fractures originated from undersaturated meteoric ground waters that migrated into the burial environment while dissolving and incorporating Ca2+ and CO3 2_ and radiogenic Sr from the dissolution of the surrounding carbonates and the felsic basement, respectively. In the burial environment, these fluids were heated and mixed with hypersaline brines from deeply buried parts of the basement. Expulsion of these fluids along basementrooted thrust faults into the overlying strata, including the Madison Formation, occurred most likely during shortening episodes of the Laramide orogeny by earthquake-induced rupturing of the host rock. The fluids were injected forcefully and in an explosive manner into the Madison Formation, causing brecciation and fracturing of the host rock, whereas the subsequent and sudden decrease in the partial pressure of CO2 caused the rapid precipitation of calcite cements. The explosive nature of hydrothermal fluid migration ultimately produces heterogeneities in reservoir-quality carbonates. In general, flow units in the Madison Formation are related to sequence boundaries, which create vertical subdivisions in the porous dolomite. The late-stage calcite cement surrounds hydrothermal breccia clasts and invades the dolomite, reducing porosity and permeability of the reservoir-quality rock. As a consequence, horizontal flow barriers and compartments are established that are locally unpredictable in their location and extent and regionally predictable along the margins of the Bighorn Basin. 

Cathedral Cave, Wellington Cave, New South Wales, Australia. A multiphase, non-fluvial cave., 2007, Osborne R. A. L.
Cathedral Cave is an outstanding example of a class of multiphase caves with largely non-fluvial origins. It contains large cavities such as cathedrals and cupolas, characteristic of excavation by convection currents in rising waters. Smaller-scale features such as rising half-tubes, pseudonotches, curved juts, projecting corners, blades and bridges indicate intersection and exhumation of older cavities during the formation of younger ones. It is possible to recognize at least ten significant phases of speleogenesis by morphostratigraphy, in addition to the four generations of cave-filling palaeokarst deposits intersected by the cave. The cave we see today results from the progressive integration of a number of previously disconnected or poorly connected solution cavities.

Hypogene Speleogenesis: hydrogeological and morphogenetic perspective. (Alexander Klimchouk, National Cave and Karst Research Institute Special Paper n. 1, 106 pages, 2007 ISBN-10 0-9795422-0-0 ISBN-13 978-0-9795422-0-6), 2007, Forti, Paolo

A review of the book: Klimchouk, A.B. Hypogene Speleogenesis: Hydrogeological and Morphogenetic Perspective

Nonsulfide and sulfide-rich zinc mineralizations in the Vazante, Ambrsia and Fagundes deposits, Minas Gerais, Brazil: Mass balance and stable isotope characteristics of the hydrothermal alterati, 2007, Soares Monteiro Lena Virgí, Nia, Bettencourt Jorge Silva, Juliani Caetano, De Oliveira Tolentino Flvio
The Vazante Group hosts the Vazante nonsulfide zinc deposit, which comprises high-grade zinc silicate ore (ZnSiO4), and late-diagenetic to epigenetic carbonate-hosted sulfide-rich zinc deposits (e.g. Morro Agudo, Fagundes, and Ambrósia). In the sulfide-rich deposits, hydrothermal alteration involving silicification and dolomitization was related with ground preparation of favorable zones for fluid migration (e.g. Fagundes) or with direct interaction with the metalliferous fluid (e.g. Ambrósia). At Vazante, hydrothermal alteration resulted in silicification and dolomite, siderite, jasper, hematite, and chlorite formation. These processes were accompanied by strong relative gains of SiO2, Fe2O3(T), Rb, Sb, V, U, and La, which are typically associated with the nonsulfide zinc mineralization. All sulfide-rich zinc ores in the district display a similar geochemical signature suggesting a common metal source from the underlying sedimentary sequences. Oxygen and carbon isotope compositions of hydrothermally altered rocks reveal a remarkable alteration halo at the Vazante deposit, which is not a notable feature in the sulfide-rich deposits. This pattern could be attributed to fluid mixing processes involving the metalliferous fluid and channelized meteoric water, which may control the precipitation of the Vazante nonsulfide ore. Sulfide deposition resulted from fluid?rock interaction processes and mixing between the ascending metalliferous fluids and sulfur-rich tectonic brines derived from reduced shale units.

Isotope geochemistry of the mafic dikes from the Vazante nonsulfide zinc deposit, Brazil, 2007, Babinski M. , Monteiro L. V. S. , Fetter A. H. , Bettencourt J. S. , Oliveir T. F.
The Vazante Group, located in the northwestern part of Minas Gerais, hosts the most important zinc mine in Brazil, the Vazante Mine, which represents a major known example of a hypogene nonsulfide zinc deposit. The main zinc ore is represented by willemite and differs substantially from other deposits of the Vazante-Paracatu region, which are sulfide-dominated zinc-lead ore. The age of the Vazante Group and the hosted mineralization is disputable. Metamorphosed mafic dikes (metabasites) that cut the metasedimentary sequence and are affected by hydrothermal processes recently were found and may shed light on the geochronology of this important geological unit. Zircon crystals recovered from the metabasites are xenocrystic grains that yield U?Pb conventional ages ranging from 2.1 to 2.4 Ga, so the basement of the Vazante Group is Paleoproterozoic or has metasedimentary rocks whose source area was Paleoproterozoic. Pb isotopes determined for titanite separated from the metabasites have common, nonradiogenic Pb compositions, which prevents determination of their crystallization age. However, the Pb signatures observed for the titanite crystals are in agreement with those determined for galena from the carbonate-hosted Zn?Pb deposits hosted by the Vazante Group, including galena from minor sulfide ore bodies of the Vazante deposit. These similarities suggest that the metalliferous fluids that affected the metabasites may have been those responsible for galena formation, which could imply a similar lead source for both nonsulfide and sulfide zinc deposits in the Vazante?Paracatu district. This common source could be related to deep-seated, basin-derived, metalliferous fluids associated with a long-lived hydrothermal system related to diagenesis and deformation of the Vazante Group during the Neoproterozoic.

Zoloushka Cave, 2007, Andreychouk V.

In March 2007 there was a 30th anniversary of a discovery of the Zoloushka (Cinderella) Cave, which is one of the largest gypsum caves in the world. Until now over 90 km of passages of a total volume of 0.65 million m3 have been mapped. The cave was accidentally encountered by the face of a gypsum quarry in 1946, but it was not penetrated by speleologists until 30 years later. From the very beginning of exploration, the cave attracted the attention of many speleologists and later - geographers and geologists. It became a notable supplement to the family of the largest gypsum caves, which were investigated in the area of the neighboring Podolsky (Podolia) region. It appeared however not entirely similar to them: as compared to the cave systems in Podolia the Zoloushka Cave shows more voluminous passages and it is more filled with clayey sediments. The cave passages developed mainly in the upper part of the gypsum layer, which resulted in collapses in many sections. The main feature of the Zoloushka Cave is that it was artificially uncovered (in the quarry face) and it was not accessible until the gypsum layer was drained by pumping out karst water. The quarry exposed rich groundwater reservoir ? a large karst aquifer. Gradual deepening and extension of the quarry caused the increase of outflow rate and the increase of water withdrawal. In the late 1960s, when the most (18-20m) of the gypsum layer (total thickness 24-26 m) was entrenched, the karst system had been already drained. Groundwater, marking the surface of a depression cone, was preserved only in the lowest parts of the cave. The karst system became accessible to investigations. Opening of the Zoloushka maze had interrupted the natural evolution of the hydrogeological settings ? it had occurred in the moment when it was almost totally filled with water. The caves in the Podolia region underwent this stage tens of thousand years earlier. Modern draining and younger age of the Zoloushka Cave determined a specific character of its internal relief (increased moisture of deposits, lack of secondary gypsum formations which are so typical for the Pololian?s caves), and caused different processes to operate (roof subsidence, sediment drying/draining, water flows between different areas, etc.), which accompanied a sudden conversion from water-filled chambers to empty ones. It became clear from the very beginning that the cave is an extremely interesting object from a scientific point of view. The cave provided a unique opportunity to carry out multi-aspect investigations. Many phenomena and features were observed by speleologists for the first time. Morphological features of the cave, such as large cylindrical pits created by rising underground water, evidence undoubtedly a confined origin of the cave system. The morphogenetic studies in the cave have played an important role in understanding problems of karst development in this region and establishing a new (artesian) regional concept of speleogenesis. The abundance of iron-manganese deposits in the cave attracted the attention of geochemists, who determined the presence of numerous geochemical processes which occurred when the cave became drained. The cave made it possible for speleologists to study the mechanisms of sinkhole development, which is extremely important for an adequate understanding and assessment of karst hazards. The cave sediments contain numerous carbonate insertions (lithified fills of relict fissures in gypsum), which make it possible to reconstruct important palaeogeographic, palaeotectonic and palaeokarstic events. During all these years the cave has been well studied. This work represents a kind of summary of all the hitherto achievements and has a general and complex character. Many problems however remained unresolved. Therefore the aim of this work is not only to present general results of the investigations which have been carried out in the Zoloushka Cave, but also to attract the interest of specialists of different fields in order to enlarge and intensify the investigations in the cave itself and its surrounding. The book's twelve chapters deal with history of the cave discovery and study, natural conditions and karst of the region, geological environment of the cave, speleomorphogenesis, morphological structure of the cave network, hydrology, breakdown processes and sinkhole development, cave sediments, cave microclimate, life in the cave, cave genesis and age, scientific and practical importance of the cave.

In Russian, with extended abstract and captions in English and Polish.

Hypogene Speleogenesis: Hydrogeological and Morphogenetic Perspective., 2007, Klimchouk A. B.

This book provides an overview of the principal environments, main processes and manifestations of hypogenic speleogenesis, and refines the relevant conceptual framework. It consolidates the notion of hypogenic karst as one of the two major types of karst systems (the other being epigenetic karst). Karst is viewed in the context of regional groundwater flow systems, which provide the systematic transport and distribution mechanisms needed to produce and maintain the disequilibrium conditions necessary for speleogenesis. Hypogenic and epigenic karst systems are regularly associated with different types, patterns and segments of flow systems, characterized by distinct hydrokinetic, chemical and thermal conditions. Epigenic karst systems are predominantly local systems, and/or parts of recharge segments of intermediate and regional systems. Hypogenic karst is associated with discharge regimes of regional or intermediate flow systems.

Various styles of hypogenic caves that were previously considered unrelated, specific either to certain lithologies or chemical mechanisms are shown to share common hydrogeologic genetic backgrounds. In contrast to the currently predominant view of hypogenic speleogenesis as a specific geochemical phenomenon, the broad hydrogeological approach is adopted in this book. Hypogenic speleogenesis is defined with reference to the source of fluid recharge to the cave-forming zone, and type of flow system. It is shown that confined settings are the principal hydrogeologic environment for hypogenic speleogenesis. However, there is a general evolutionary trend for hypogenic karst systems to lose their confinement due to uplift and denudation and due to their own expansion. Confined hypogenic caves may experience substantial modification or be partially or largely overprinted under subsequent unconfined (vadose) stages, either by epigenic processes or continuing unconfined hypogenic processes, especially when H2S dissolution mechanisms are involved.

Hypogenic confined systems evolve to facilitate cross-formational hydraulic communication between common aquifers, or between laterally transmissive beds in heterogeneous soluble formations, across cave-forming zones. The latter originally represented low-permeability, separating units supporting vertical rather than lateral flow. Layered heterogeneity in permeability and breaches in connectivity between different fracture porosity structures across soluble formations are important controls over the spatial organization of evolving ascending hypogenic cave systems. Transverse hydraulic communication across lithological and porosity system boundaries, which commonly coincide with major contrasts in water chemistry, gas composition and temperature, is potent enough to drive various disequilibrium and reaction dissolution mechanisms. Hypogenic speleogenesis may operate in both carbonates and evaporites, but also in some clastic rocks with soluble cement. Its main characteristic is the lack of genetic relationship with groundwater recharge from the overlying or immediately adjacent surface. It may not be manifest at the surface at all, receiving some expression only during later stages of uplift and denudation. In many instances, hypogenic speleogenesis is largely climate- independent.

There is a specific hydrogeologic mechanism inherent in hypogenic transverse speleogenesis (restricted input/output) that suppresses the positive flow-dissolution feedback and speleogenetic competition in an initial flowpath network. This accounts for the development of more pervasive channeling and maze patterns in confined settings where appropriate structural prerequisites exist. As forced-flow regimes in confined settings are commonly sluggish, buoyancy dissolution driven by either solute or thermal density differences is important in hypogenic speleogenesis.

In identifying hypogenic caves, the primary criteria are morphological (patterns and meso-morphology) and hydrogeological (hydrostratigraphic position and recharge/flow pattern viewed from the perspective of the evolution of a regional groundwater flow system). Elementary patterns typical for hypogenic caves are network mazes, spongework mazes, irregular chambers and isolated passages or crude passage clusters. They often combine to form composite patterns and complex 3- D structures. Hypogenic caves are identified in various geological and tectonic settings, and in various lithologies. Despite these variations, resultant caves demonstrate a remarkable similarity in cave patterns and meso-morphology, which strongly suggests that the hydrogeologic settings were broadly identical in their formation. Presence of the characteristic morphologic suites of rising flow with buoyancy components is one of the most decisive criteria for identifying hypogenic speleogenesis, which is much more widespread than was previously presumed. Hypogenic caves include many of the largest, by integrated length and by volume, documented caves in the world.

The refined conceptual framework of hypogenic speleogenesis has broad implications in applied fields and promises to create a greater demand for karst and cave expertise by practicing hydrogeology, geological engineering, economic geology, and mineral resource industries. Any generalization of the hydrogeology of karst aquifers, as well as approaches to practical issues and resource prospecting in karst regions, should take into account the different nature and characteristics of hypogenic and epigenic karst systems. Hydraulic properties of karst aquifers, evolved in response to hypogenic speleogenesis, are characteristically different from epigenic karst aquifers. In hypogenic systems, cave porosity is roughly an order of magnitude greater, and areal coverage of caves is five times greater than in epigenic karst systems. Hypogenic speleogenesis commonly results in more isotropic conduit permeability pervasively distributed within highly karstified areas measuring up to several square kilometers. Although being vertically and laterally integrated throughout conduit clusters, hypogenic systems, however, do not transmit flow laterally for considerable distances. Hypogenic speleogenesis can affect regional subsurface fluid flow by greatly enhancing initially available cross- formational permeability structures, providing higher local vertical hydraulic connections between lateral stratiform pathways for groundwater flow, and creating discharge segments of flow systems, the areas of low- fluid potential recognizable at the regional scale. Discharge of artesian karst springs, which are modern outlets of hypogenic karst systems, is often very large and steady, being moderated by the high karstic storage developed in the karstified zones and by the hydraulic capacity of an entire artesian system. Hypogenic speleogenesis plays an important role in conditioning related processes such as hydrothermal mineralization, diagenesis, and hydrocarbon transport and entrapment.

An appreciation of the wide occurrence of hypogenic karst systems, marked specifics in their origin, development and characteristics, and their scientific and practical importance, calls for revisiting and expanding the current predominantly epigenic paradigm of karst and cave science.

Solution-collapse breccia pipes are common features in northwestern Arizona. They were mineralized with uranium, but associated with it are a suite of elements (e.g., As, Mo, V, Ba, Cu, Pb, and Fe) that may form other ore minerals. Breccia bodies are in some cases cut by cave passages, such as at Corkscrew Cave, Arizona, where such structures are exposed along the walls and on the cave ceilings. The abundance of gypsum and barite throughout the cave and their isotopically light 34S value (?11 to ?7) suggest deposition from warm sulfidic solutions that were also responsible, at least in part, for development of the recent cave passages that dissect older paleokarst breccia bodies. The presence of calcite showing depleted 18O values (?11.3 and ?16.9) is considered indicative of a low-temperature hydrothermal episode in the deposition history of cave minerals. Groundwater percolating through the breccia-pipe bodies mobilized and transported ore-related ions into the cave, where they formed a unique assemblage of minerals (i.e., hörnesite, talmessite, carnotite, tyuyamunite, claudetite, and powellite) that mirror breccia-pipe mineralization.

Results 31 to 45 of 276
You probably didn't submit anything to search for