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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. ...

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That capillary percolation is see imbibition.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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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 volcanism (Keyword) returned 25 results for the whole karstbase:
Showing 16 to 25 of 25
Le problme de louverture des vides initiaux pr-karstiques: cas de la dolomie siliceuse du Sous-Groupe de Malmani, Afrique du Sud., 2007, Martini J.
THE PROBLEM RELATED TO THE INITIAL SIZE OF THE PRE-KARSTIC VOIDS: THE CASE OF THE SILICEOUS DOLOSTONE OF THE MALMANI SUBGROUP, SOUTH AFRICA. The paper describes pre-karstic jointing in phreatic mazes developed in a Precambrian siliceous dolostone. The initial joint opening controling the speleogenesis can be measured in chert seams interstratified within the dolostone, since they are practically unaffected by karst dissolution. The measured openings generally vary from 0.3 to 5.0 mm, although values up to 30 mm have been recorded. The origin of the jointing has been linked to a Liassic tentional event which affected the entire African Austral sub-continent. This event is also associated with a major basaltic volcanism of the fissural type. Due to the exceptional nature of this tentionnal event, it appears difficult to compare the figures given here with the openings given by the authors from karst domains elsewhere in the world, who quote figures 1 to 2 magnitudes smaller.

GIANT COLLAPSE STRUCTURES FORMED BY HYPOGENIC KARSTIFICATION: THE OBRUKS OF THE CENTRAL ANATOLIA, TURKEY, 2009, Bayari S. , Ozyurt N. , Pekkans E.

Assessment of the tectonic, geologic and hydrogeologic processes reveal that the Obruks, mega collapse dolines located in the central Anatolia-Turkey, are products of hypogenic karsti?cation. Obruks are characterized by their cylindrical or truncated cone shapes with diameters and depths reaching several hundreds of meters. Geological, geophysical and hydrogeological data, along with the groundwater’s chemical and isotopic composition suggest a hypogene karsti?cation process that seems to be driven by the upward migration of a deep-seated carbon dioxide ?ux supplied by an asthenospheric rise. The linear distribution of obruks through the suture zone of a former oceanic subduction and their association with young volcanism reveal a tecto-genetic origin that is related to the extensional thinning of the upper lithosphere due to orogenic collapse of the Taurus Mountain Range, which is a part of the Alpine-Himalayan Orogenic Belt.


KRASOVA JASKYNA PRYA V STIAVNICKYCH VRCHOCH - HYDROTERMALNA SPELEOGENEZA V KARBONATOVOM PODLOZI MIOCENNEHO STRATOVULKANU, 2011, Bella P. , Sucha V. , Gaal E. , Kodera P.

A cave of hydrothermal origin in crystalline limestone has been investigated near Sklene Teplice Spa in the Stiavnicke vrchy Mts. located in Central Slovakia. Metamorphozed Middle Triassic carbonate rocks occur as a horizon in pre-volcanic basement of Middle Miocene volcanic formations. The hydrothermal origin of studied cave is documented by spherical and irregural oval phreatic morphology sculptured by ascending thermal water, metamorphic type of the host rocks and their hydrothermal alteration, occurrence of large calcite and quartz crystals, and hydrothermal clays with three mineral smectite-kaolinite, illite and goethite associations. The primary phases of speleogenesis in the crystalline limestones was caused by hydrothermal processes linked either to the emplacement of granodiorite subvolcanic intrusions during the Late Badenian time or to epithermal system of the Late Sarmatian time in the central zone of the Stiavnica stratovolcano. The described cave presents the remarkable' example of hydrothermal limestone cave associated with Miocene volcanism and magmatic intrusions in Central Slovakia.
 


Hydrogeological approach to distinguishing hypogene speleogenesis settings, 2013, Klimchouk, A. B.

The hydrogeological approach to defining hypogene speleogenesis (HS) relates it to ascending groundwater flow (AF). HS develops where AF causes local disequilibria conditions favoring dissolution and supports them during sufficiently long time in course of the geodynamic and hydrogeological evolution. The disequilibrium conditions at depth are invoked by changing physical-chemical parameters along an AF paths, or/and by the interaction between circulation systems of different scales and hydrody-namic regimes. The association of HS with AF suggests a possibility to discern regulari-ties of development and distribution of HS from the perspectives of the regional hy-drogeological analysis. In mature artesian basins of the cratonic type, settings favorable for AF and HS, are as follows: 1) marginal areas of discharge of the groundwaters of the 2nd hydrogeological story (H-story), 2) zones of topography-controlled upward cir-culation within the internal basin area (at the 1st and, in places, at the 2nd H-stories; 3) crests of anticlinal folds or uplifted tectonic blocs within the internal basin area where the upper regional aquitard is thinned or partially breached; 4) linear-local zones of deep-rooted cross-formational faults conducting AF from internal deep sources across the upper H-stories. Hydrodynamics in the 3rd and 4th stories is dominated by ascending circulation strongly controlled by cross-formational tectonic structures. Specific circula-tion pattern develops in large Cenozoic carbonate platforms (the Florida-type), side-open to the ocean, where AF across stratified sequences in the coastal parts, driven by both topography-induced head gradients and density gradients, involves mixing with the seawater. The latter can be drawn into a platform at deep levels and rise in the plat-form interior (the Kohout’s scheme). In folded regions, AF and HS are tightly con-trolled by faults, especially those at junctions between large tectonic structures. In young intramontaine basins with dominating geostatic regime, HS is favored at margin-al discharge areas where circulation systems of different origins and regimes may inter-act, such as meteoric waters flows from adjacent uplifted massifs, basinal fluids expelled from the basin’s interiors, and endogenous fluids rising along deep-rooted faults. Spe-cific and very favorable settings for HS are found in regions of young volcanism with carbonate formations in a sedimentary cover


HYPOGENE PALEOKARST IN THE TRIASSIC OF THE DOLOMITES (NORTHERN ITALY), 2014, Riva, A.

In the Triassic of successions of the Italian Dolomites (Northern Italy), there are several examples of different types of hypogene paleokarst, sometimes associated with sulfur or hematite ore deposits.The paleokarst features are related to a regional volcanic event occurred during the Ladinian (Middle Triassic) that affected several carbonate platforms of Anisian-Ladinian age.This study is focusing mainly on the Latemar paleokarst, in the Western Dolomites, and on the Salafossa area in the Easternmost Dolomites.
The karst at Latemar developed as the result of a magmatic intrusion located just below the isolated carbonate platform, developing a system of phreatic conduits and some underground chambers, not justified by the entity of the submarine exposure occurring at the top of the carbonate platform. Most of these features are located about 500 m below the subaerial unconformity and are filled with middle Triassic lavas. Only in one case, the filling is represented by banded crusts now totally dolomitized, with abundant hematite. In this case, the only way to explain the presence of the karst at this depth is to invoke a deep CO2 source allowing the dissolution of the carbonate at such depths: the fact that some phreatic conduits and a possible underground chamber are filled only with lavas is pointing toward an important role of volcanism in karst development.
Salafossa is a well-known mine located in the easternmost Dolomites and has been exploited until 1986, when all the activity ceased. The main metals, in this case, are Zn-Pb-Ba-Fe, exploited within a quite complex paleokarst system developed in several levels, filled by a complex mineralized sequence. The strong dissolution led to the development of voids aligned with the main fault controlling the mineralization, with a proper karst system with phreatic morphologies.


Volcanism-induced karst landforms and speleogenesis, in the Ankarana Plateau (Madagascar). Hypothesis and preliminary research., 2014,

The Ankarana is a limestone plateau in the northern part of Madagascar, where a cave system, more than 120 km long, has been explored. The plateau is bordered by volcanoes and is cut across by several canyons. An analysis of surface landforms and caves suggests that the karst genesis was probably initiated by volcanism beneath an impervious cover. Volcanic bulging and magma intrusions may have favored a basalt-limestone assimilation process and metamorphism. The ascent of deep volcanic fluids (CO2 and SO2) from magma degassing and from limestone metamorphism, may explain the speleogenesis. Once denuded, the karst evolved classically, but the selective erosion of metamorphosed rocks (more likely to be weathered than pure limestone), resulted in the creation of unusual landforms such as canyons and large circular basins.


Research frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patterns, 2015,

Speleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO2 soil production are dominant, whereas hypogenic caves resulting from uprising deep flow not directly connected to adjacent recharge areas appear to be more frequent than previously considered. The conceptual models of epigenic cave development moved from early models, through the “four-states model” involving fracture influence to explain deep loops, to the digital models demonstrating the adjustment of the main flow to the water table. The relationships with base level are complex and cave levels must be determined from the elevation of the vadose-phreatic transitions. Since flooding in the epiphreatic zone may be important, the top of the loops in the epiphreatic zone can be found significantly high above the base level. The term Paragenesis is used to describe the upward development of conduits as their lower parts fill with sediments. This process often records a general baselevel rise. Sediment influx is responsible for the regulation of long profiles by paragenesis and contributes to the evolution of profiles from looping to water table caves. Dating methods allow identification of the timing of cave level evolution. The term Ghost-rock karstification is used to describe a 2-phase process of speleogenesis, with a first phase of partial solution of rock along fractures in low gradient conditions leaving a porous matrix, the ghost-rock, then a second phase of mechanical removing of the ghost-rock mainly by turbulent flow in high gradient conditions opening the passages and forming maze caves. The first weathering phase can be related either to epigenic infiltration or to hypogenic upflow, especially in marginal areas of sedimentary basins. The vertical pattern of epigenic caves is mainly controlled by timing, geological structure, types of flow and base-level changes. We define several cave types as (1) juvenile, where they are perched above underlying aquicludes; (2) looping, where recharge varies greatly with time, to produce epiphreatic loops; (3) water-table caves where flow is regulated by a semi-pervious cover; and (4) caves in the equilibrium stage where flow is transmitted without significant flooding. Successive base-level drops caused by valley entrenchment make cave levels, whereas baselevel rise is defined in the frame of the Per ascensum Model of Speleogenesis (PAMS), where deep passages are flooded and drain through vauclusian springs. The PAMS can be active after any type of baselevel rise (transgression, fluvial aggradation, tectonic subsidence) and explains most of the deep phreatic cave systems except for hypogenic.

The term Hypogenic speleogenesis is used to describe cave development by deep upflow independent of adjacent recharge areas. Due to its deep origin, water frequently has a high CO2-H2S concentration and a thermal anomaly, but not systemati­cally. Numerous dissolution processes can be involved in hypogenic speleogenesis, which often include deep-seated acidic sources of CO2 and H2S, “hydrothermal” cooling, mixing corrosion, Sulfuric Acid Speleogenesis (SAS), etc. SAS particularly involves the condensation-corrosion processes, resulting in the fast expansion of caves above the water table, i.e. in an atmo­spheric environment. The hydrogeological setting of hypogenic speleogenesis is based on the Regional Gravity Flow concept, which shows at the basin scales the sites of convergences and upflows where dissolution focuses. Each part of a basin (mar­ginal, internal, deep zone) has specific conditions. The coastal basin is a sub-type. In deformed strata, flow is more complex according to the geological structure. However, upflow and hypogenic speleogenesis concentrate in structural highs (buried anticlines) and zones of major disruption (faults, overthrusts). In disrupted basins, the geothermal gradient “pumps” the me­teoric water at depth, making loops of different depths and characteristics. Volcanism and magmatism also produce deep hypogenic loops with “hyperkarst” characteristics due to a combination of deep-seated CO2, H2S, thermalism, and microbial activity. In phreatic conditions, the resulting cave patterns

can include geodes, 2–3D caves, and giant ascending shafts. Along the water table, SAS with thermal air convection induces powerful condensation-corrosion and the development of upwardly dendritic caves, isolated chambers, water table sulfuricacid caves. In the vadose zone, “smoking” shafts evolve under the influence of geothermal gradients producing air convectionand condensation-corrosion.

Likely future directions for research will probably involve analytical and modeling methods, especially using isotopes, dating, chemical simulations, and field investigations focused on the relationships between processes and resulting morphologies.


Research frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patterns, 2015,

Speleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO2 soil production are dominant, whereas hypogenic caves resulting from uprising deep flow not directly connected to adjacent recharge areas appear to be more frequent than previously considered. The conceptual models of epigenic cave development moved from early models, through the “four-states model” involving fracture influence to explain deep loops, to the digital models demonstrating the adjustment of the main flow to the water table. The relationships with base level are complex and cave levels must be determined from the elevation of the vadose-phreatic transitions. Since flooding in the epiphreatic zone may be important, the top of the loops in the epiphreatic zone can be found significantly high above the base level. The term Paragenesis is used to describe the upward development of conduits as their lower parts fill with sediments. This process often records a general baselevel rise. Sediment influx is responsible for the regulation of long profiles by paragenesis and contributes to the evolution of profiles from looping to water table caves. Dating methods allow identification of the timing of cave level evolution. The term Ghost-rock karstification is used to describe a 2-phase process of speleogenesis, with a first phase of partial solution of rock along fractures in low gradient conditions leaving a porous matrix, the ghost-rock, then a second phase of mechanical removing of the ghost-rock mainly by turbulent flow in high gradient conditions opening the passages and forming maze caves. The first weathering phase can be related either to epigenic infiltration or to hypogenic upflow, especially in marginal areas of sedimentary basins. The vertical pattern of epigenic caves is mainly controlled by timing, geological structure, types of flow and base-level changes. We define several cave types as (1) juvenile, where they are perched above underlying aquicludes; (2) looping, where recharge varies greatly with time, to produce epiphreatic loops; (3) water-table caves where flow is regulated by a semi-pervious cover; and (4) caves in the equilibrium stage where flow is transmitted without significant flooding. Successive base-level drops caused by valley entrenchment make cave levels, whereas baselevel rise is defined in the frame of the Per ascensum Model of Speleogenesis (PAMS), where deep passages are flooded and drain through vauclusian springs. The PAMS can be active after any type of baselevel rise (transgression, fluvial aggradation, tectonic subsidence) and explains most of the deep phreatic cave systems except for hypogenic.

The term Hypogenic speleogenesis is used to describe cave development by deep upflow independent of adjacent recharge areas. Due to its deep origin, water frequently has a high CO2-H2S concentration and a thermal anomaly, but not systemati­cally. Numerous dissolution processes can be involved in hypogenic speleogenesis, which often include deep-seated acidic sources of CO2 and H2S, “hydrothermal” cooling, mixing corrosion, Sulfuric Acid Speleogenesis (SAS), etc. SAS particularly involves the condensation-corrosion processes, resulting in the fast expansion of caves above the water table, i.e. in an atmo­spheric environment. The hydrogeological setting of hypogenic speleogenesis is based on the Regional Gravity Flow concept, which shows at the basin scales the sites of convergences and upflows where dissolution focuses. Each part of a basin (mar­ginal, internal, deep zone) has specific conditions. The coastal basin is a sub-type. In deformed strata, flow is more complex according to the geological structure. However, upflow and hypogenic speleogenesis concentrate in structural highs (buried anticlines) and zones of major disruption (faults, overthrusts). In disrupted basins, the geothermal gradient “pumps” the me­teoric water at depth, making loops of different depths and characteristics. Volcanism and magmatism also produce deep hypogenic loops with “hyperkarst” characteristics due to a combination of deep-seated CO2, H2S, thermalism, and microbial activity. In phreatic conditions, the resulting cave patterns

can include geodes, 2–3D caves, and giant ascending shafts. Along the water table, SAS with thermal air convection induces powerful condensation-corrosion and the development of upwardly dendritic caves, isolated chambers, water table sulfuricacid caves. In the vadose zone, “smoking” shafts evolve under the influence of geothermal gradients producing air convectionand condensation-corrosion.

Likely future directions for research will probably involve analytical and modeling methods, especially using isotopes, dating, chemical simulations, and field investigations focused on the relationships between processes and resulting morphologies.


Research frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patterns, 2015,

Speleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO2 soil production are dominant, whereas hypogenic caves resulting from uprising deep flow not directly connected to adjacent recharge areas appear to be more frequent than previously considered. The conceptual models of epigenic cave development moved from early models, through the “four-states model” involving fracture influence to explain deep loops, to the digital models demonstrating the adjustment of the main flow to the water table. The relationships with base level are complex and cave levels must be determined from the elevation of the vadose-phreatic transitions. Since flooding in the epiphreatic zone may be important, the top of the loops in the epiphreatic zone can be found significantly high above the base level. The term Paragenesis is used to describe the upward development of conduits as their lower parts fill with sediments. This process often records a general baselevel rise. Sediment influx is responsible for the regulation of long profiles by paragenesis and contributes to the evolution of profiles from looping to water table caves. Dating methods allow identification of the timing of cave level evolution. The term Ghost-rock karstification is used to describe a 2-phase process of speleogenesis, with a first phase of partial solution of rock along fractures in low gradient conditions leaving a porous matrix, the ghost-rock, then a second phase of mechanical removing of the ghost-rock mainly by turbulent flow in high gradient conditions opening the passages and forming maze caves. The first weathering phase can be related either to epigenic infiltration or to hypogenic upflow, especially in marginal areas of sedimentary basins. The vertical pattern of epigenic caves is mainly controlled by timing, geological structure, types of flow and base-level changes. We define several cave types as (1) juvenile, where they are perched above underlying aquicludes; (2) looping, where recharge varies greatly with time, to produce epiphreatic loops; (3) water-table caves where flow is regulated by a semi-pervious cover; and (4) caves in the equilibrium stage where flow is transmitted without significant flooding. Successive base-level drops caused by valley entrenchment make cave levels, whereas baselevel rise is defined in the frame of the Per ascensum Model of Speleogenesis (PAMS), where deep passages are flooded and drain through vauclusian springs. The PAMS can be active after any type of baselevel rise (transgression, fluvial aggradation, tectonic subsidence) and explains most of the deep phreatic cave systems except for hypogenic.

The term Hypogenic speleogenesis is used to describe cave development by deep upflow independent of adjacent recharge areas. Due to its deep origin, water frequently has a high CO2-H2S concentration and a thermal anomaly, but not systemati­cally. Numerous dissolution processes can be involved in hypogenic speleogenesis, which often include deep-seated acidic sources of CO2 and H2S, “hydrothermal” cooling, mixing corrosion, Sulfuric Acid Speleogenesis (SAS), etc. SAS particularly involves the condensation-corrosion processes, resulting in the fast expansion of caves above the water table, i.e. in an atmo­spheric environment. The hydrogeological setting of hypogenic speleogenesis is based on the Regional Gravity Flow concept, which shows at the basin scales the sites of convergences and upflows where dissolution focuses. Each part of a basin (mar­ginal, internal, deep zone) has specific conditions. The coastal basin is a sub-type. In deformed strata, flow is more complex according to the geological structure. However, upflow and hypogenic speleogenesis concentrate in structural highs (buried anticlines) and zones of major disruption (faults, overthrusts). In disrupted basins, the geothermal gradient “pumps” the me­teoric water at depth, making loops of different depths and characteristics. Volcanism and magmatism also produce deep hypogenic loops with “hyperkarst” characteristics due to a combination of deep-seated CO2, H2S, thermalism, and microbial activity. In phreatic conditions, the resulting cave patterns

can include geodes, 2–3D caves, and giant ascending shafts. Along the water table, SAS with thermal air convection induces powerful condensation-corrosion and the development of upwardly dendritic caves, isolated chambers, water table sulfuricacid caves. In the vadose zone, “smoking” shafts evolve under the influence of geothermal gradients producing air convectionand condensation-corrosion.

Likely future directions for research will probably involve analytical and modeling methods, especially using isotopes, dating, chemical simulations, and field investigations focused on the relationships between processes and resulting morphologies.


Research frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patterns, 2015,

Speleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO2 soil production are dominant, whereas hypogenic caves resulting from uprising deep flow not directly connected to adjacent recharge areas appear to be more frequent than previously considered. The conceptual models of epigenic cave development moved from early models, through the “four-states model” involving fracture influence to explain deep loops, to the digital models demonstrating the adjustment of the main flow to the water table. The relationships with base level are complex and cave levels must be determined from the elevation of the vadose-phreatic transitions. Since flooding in the epiphreatic zone may be important, the top of the loops in the epiphreatic zone can be found significantly high above the base level. The term Paragenesis is used to describe the upward development of conduits as their lower parts fill with sediments. This process often records a general baselevel rise. Sediment influx is responsible for the regulation of long profiles by paragenesis and contributes to the evolution of profiles from looping to water table caves. Dating methods allow identification of the timing of cave level evolution. The term Ghost-rock karstification is used to describe a 2-phase process of speleogenesis, with a first phase of partial solution of rock along fractures in low gradient conditions leaving a porous matrix, the ghost-rock, then a second phase of mechanical removing of the ghost-rock mainly by turbulent flow in high gradient conditions opening the passages and forming maze caves. The first weathering phase can be related either to epigenic infiltration or to hypogenic upflow, especially in marginal areas of sedimentary basins. The vertical pattern of epigenic caves is mainly controlled by timing, geological structure, types of flow and base-level changes. We define several cave types as (1) juvenile, where they are perched above underlying aquicludes; (2) looping, where recharge varies greatly with time, to produce epiphreatic loops; (3) water-table caves where flow is regulated by a semi-pervious cover; and (4) caves in the equilibrium stage where flow is transmitted without significant flooding. Successive base-level drops caused by valley entrenchment make cave levels, whereas baselevel rise is defined in the frame of the Per ascensum Model of Speleogenesis (PAMS), where deep passages are flooded and drain through vauclusian springs. The PAMS can be active after any type of baselevel rise (transgression, fluvial aggradation, tectonic subsidence) and explains most of the deep phreatic cave systems except for hypogenic.

The term Hypogenic speleogenesis is used to describe cave development by deep upflow independent of adjacent recharge areas. Due to its deep origin, water frequently has a high CO2-H2S concentration and a thermal anomaly, but not systemati­cally. Numerous dissolution processes can be involved in hypogenic speleogenesis, which often include deep-seated acidic sources of CO2 and H2S, “hydrothermal” cooling, mixing corrosion, Sulfuric Acid Speleogenesis (SAS), etc. SAS particularly involves the condensation-corrosion processes, resulting in the fast expansion of caves above the water table, i.e. in an atmo­spheric environment. The hydrogeological setting of hypogenic speleogenesis is based on the Regional Gravity Flow concept, which shows at the basin scales the sites of convergences and upflows where dissolution focuses. Each part of a basin (mar­ginal, internal, deep zone) has specific conditions. The coastal basin is a sub-type. In deformed strata, flow is more complex according to the geological structure. However, upflow and hypogenic speleogenesis concentrate in structural highs (buried anticlines) and zones of major disruption (faults, overthrusts). In disrupted basins, the geothermal gradient “pumps” the me­teoric water at depth, making loops of different depths and characteristics. Volcanism and magmatism also produce deep hypogenic loops with “hyperkarst” characteristics due to a combination of deep-seated CO2, H2S, thermalism, and microbial activity. In phreatic conditions, the resulting cave patterns

can include geodes, 2–3D caves, and giant ascending shafts. Along the water table, SAS with thermal air convection induces powerful condensation-corrosion and the development of upwardly dendritic caves, isolated chambers, water table sulfuricacid caves. In the vadose zone, “smoking” shafts evolve under the influence of geothermal gradients producing air convectionand condensation-corrosion.

Likely future directions for research will probably involve analytical and modeling methods, especially using isotopes, dating, chemical simulations, and field investigations focused on the relationships between processes and resulting morphologies.


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