Hydrothermal Speleogenesis– Its Settings and Peculiar Features (original) (raw)
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Le karst hydrothermal d'Aix-les-Bains (Savoie, France)
2008
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International Journal of Speleology, 2024
The Berenike hypogenic cave system near Lake Kinneret, Israel, provides a valuable case study for investigating the recently proposed Confined-Cooling-Flow (CCF) speleogenesis model. Field and speleological surveys, along with existing research, are used to provide a thorough analysis. The CCF model relies on a simple thermo-hydro-chemical scenario, involving the rise of CO 2-rich hydrothermal fluids discharging into a confined layer. The cooling of these CO 2-rich fluids turns them into aggressive solutions due to the inverse relation between temperature and solubility of carbonates (retrograde solubility). Previous geochemical and numerical analyses of the CCF model predict localized and persistent dissolution and speleogenesis on short geologic timescales and reproduce common characteristics of hypogene cave morphology. The present study examines speleogenesis in Berenike by correlating it spatially and temporally with the geologic history and hydrogeology of the region and refers to the cave location and appearance in the rock section. The relatively clear and preserved morphologic features at various scales allow for further insights. Particularly, the CCF model can explain enigmatic field observations, such as the location of the largest passages at some distance away from the feeder. It also accounts for the formation of intricate maze-like networks in soluble rock successions and confined conditions, not explained by other models. Finally, this study suggests that the CCF model has broader applicability in understanding the formation of numerous large hypogenic karst and maze cave systems that are globally widespread. Hypogene speleogenesis, Cooling hydrothermal flow, Maze caves, Numerical modelling
Speleogenetic history of the Hungarian hydrothermal karst
Environmental Geology, 1995
The hydrothermal karst of Hungary displays at least two principal stages of development in two differing environments. Caves of an early stage were formed within a deep zone of low thermal gradient. These caves (vugs) are small (tens of centimeters) and lined with scalenohedral crystals of calcite that are often in association with barite. Calcite yields fluid inclusion temperatures of 55-95~ and is depleted in a80 (-11.2 to -17.6 per mil PDB). The caves were formed by ascending thermal waters charged with CO2. Solubility of CaCO3 in such a system gradually increases with the ascent of the fluid (solutional zone) but drops sharply at a depth of -250 m to -500 m below the water surface (depositional zone). Caves formed in the solutional zone may be shifted into the depositional zone due to tectonic uplift, and calcite lines their walls. Large caves (tens to thousands of cubic meters) of a late stage were formed within a shallow zone of high thermal gradient immediately below and above the thermal water table. The calcite of the phreatic crusts has a rhombohedral habit, displays lower fluid inclusion temperatures (35-55~ and less), and a depletion in 1so of -9.5 to -14.6 per mil PDB. Several powerful cave-forming processes may operate there including convection, mixing/cooling corrosion, and condensation corrosion. Due to differences in the rate of tectonic uplift, rate of hydrothermal system decay, and hydrogeologic pattern, these caves were either filled with water for a long period of time (phreatic calcite crusts are formed) or partly dewatered early in their history (waterline and subaerial speleothems are formed). The zones of thermal cave formation recognized in Hungary may have a universal character. Very similar features are found in other hydrothermal karst areas of the world (Kirghizia, Algeria, South Dakota). Key words Paleohydrogeology 9 Hydrothermal karst 9 Calcite" Fluid inclusions'Hungary Y. V. Dublyansky ([~<])
6.6 Karstification by Geothermal Waters
Treatise on Geomorphology, 2013
Forms related to air movement 6.6.6.4.2 Forms related to uniform surface attack 6.6.6.4.3 Forms related to condensation runoff and dripping 6.6.7 Conclusions References
Author's personal copy Morphogenesis of hypogenic caves
Hypogenic speleogenesis is the formation of solution-enlarged permeability structures by waters ascending to a cave-forming zone from below in leaky confined conditions, where deeper groundwaters in regional or intermediate flow systems interact with shallower and more local groundwater flow systems. This is in contrast to more familiar epigenic speleogenesis which is dominated by shallow groundwater systems receiving recharge from the overlying or immediately adjacent surface. Hypogenic caves are identified in various geological and tectonic settings, formed by different dissolutional mechanisms operating in various lithologies. Despite these variations, resultant caves demonstrate a remarkable similarity in patterns and meso-morphology, which strongly suggests that the hydrogeologic settings were broadly identical in their formation. Hypogenic caves commonly demonstrate a characteristic suite of cave morphologies resulting from rising flow across the cave-forming zone with distinct buoyancydissolution components. In addition to hydrogeological criteria (hydrostratigraphic position, rechargedischarge configuration and flow pattern viewed from the perspective of the evolution of a regional groundwater flow system), morphogenetic analysis is the primary tool in identifying hypogenic caves. Cave patterns resulting from ascending transverse speleogenesis are strongly guided by the permeability structure in a cave formation. They are also influenced by the discordance of permeability structure in the adjacent beds and by the overall hydrostratigraphic arrangement. Three-dimensional mazes with multiple storeys, or complex 3-D cave systems are most common, although single isolated chambers, passages or crude clusters of a few intersecting passages may occur where fracturing is scarce and laterally discontinuous. Large rising shafts and collapse sinkholes over large voids, associated with deep hydrothermal systems, are also known. Hypogenic caves include many of the largest, by integrated length and by volume, documented caves in the world. More importantly, hypogenic speleogenesis is much more widespread than it was previously presumed. Growing recognition of hypogenic speleogenesis and improved understanding of its peculiar characteristics has an immense importance to both karst science and applied fields as it promises to answer many questions about karst porosity (especially as deep-seated settings are concerned) which remained poorly addressed within the traditional epigenetic karst paradigm.
Morphogenesis of hypogenic caves
Geomorphology, 2009
Hypogenic speleogenesis is the formation of solution-enlarged permeability structures by waters ascending to a cave-forming zone from below in leaky confined conditions, where deeper groundwaters in regional or intermediate flow systems interact with shallower and more local groundwater flow systems. This is in contrast to more familiar epigenic speleogenesis which is dominated by shallow groundwater systems receiving recharge from the overlying or immediately adjacent surface.Hypogenic caves are identified in various geological and tectonic settings, formed by different dissolutional mechanisms operating in various lithologies. Despite these variations, resultant caves demonstrate a remarkable similarity in patterns and meso-morphology, which strongly suggests that the hydrogeologic settings were broadly identical in their formation. Hypogenic caves commonly demonstrate a characteristic suite of cave morphologies resulting from rising flow across the cave-forming zone with distinct buoyancy-dissolution components. In addition to hydrogeological criteria (hydrostratigraphic position, recharge–discharge configuration and flow pattern viewed from the perspective of the evolution of a regional groundwater flow system), morphogenetic analysis is the primary tool in identifying hypogenic caves.Cave patterns resulting from ascending transverse speleogenesis are strongly guided by the permeability structure in a cave formation. They are also influenced by the discordance of permeability structure in the adjacent beds and by the overall hydrostratigraphic arrangement. Three-dimensional mazes with multiple storeys, or complex 3-D cave systems are most common, although single isolated chambers, passages or crude clusters of a few intersecting passages may occur where fracturing is scarce and laterally discontinuous. Large rising shafts and collapse sinkholes over large voids, associated with deep hydrothermal systems, are also known.Hypogenic caves include many of the largest, by integrated length and by volume, documented caves in the world. More importantly, hypogenic speleogenesis is much more widespread than it was previously presumed. Growing recognition of hypogenic speleogenesis and improved understanding of its peculiar characteristics has an immense importance to both karst science and applied fields as it promises to answer many questions about karst porosity (especially as deep-seated settings are concerned) which remained poorly addressed within the traditional epigenetic karst paradigm.
Bulletin de la Societe Geologique de France, 2010
Aix-les-Bains (Savoie, France) owes its name and reputation to the thermal springs that occur along the eastern shore of Lake Bourget, France largest natural lake. Although the city waters have been exploited since Antiquity, scientific investigations into the nature and characteristics of the hydrothermal karst from which they emerge did not begin until the early 19th century. The present article traces the history of these investigations and summarizes the results of more than two centuries of scientific research. Today, the only visible signs of karstification related to hydrothermal flows are to be found in the discharge zone in the Urgonian limestone anticline that rises above the city centre. These features are: – the Grotte des Serpents, which houses the Alun Spring, the system main natural discharge, – the Chevalley Aven, a blind chimney that was accidentally uncovered in 1996, – other hydrothermal springs that are too small to enter, including the Soufre Spring. Although sc...
A Hydrothermal Model of Rapid Post-Flood Karsting
2003
Existing karstogenetic models have not explained the inception and development of global karst, especially the origin and occurrence of extensive secondary porosity and flowpaths. Karstogenesis appears to be explainable by proposing a hypogene model of origin, previous to the exogene one. Known to ore geologists for a long time, hydrothermal karsting could very well be responsible for global karsting, provided a global hydrothermal activity. The geological conditions towards the end of the Flood and immediately after may well have included such widespread hydrothermalism and if so, rapid karsting would have resulted. Post-Flood karstogenesis was also boosted by acids produced by decay of huge quantities of organic matter. Present day ocean bottom hydrothermal vents have been found to extract actively calcium from igneous rocks and to redeposit it as carbonate chimneys. This confirms the acidic character of hydrothermal solutions and supports a rapid hydrothermal karsting model. Hydr...
Acta Carsologica, 2015
UDC 551.435.84 Philippe Audra & Arthur N. Palmer: Research frontiers in speleogenesis. Dominant processes, hydrogeological conditions and resulting cave patterns Speleogenesis is the development of well-organized cave systems by fluids moving through fissures of a soluble rock. Epigenic caves induced by biogenic CO 2 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
Hypogene Karst Regions and Caves of the World
Hypogene Karst Regions and Caves of the World, 2017
This book illustrates the diversity of hypogene speleogenetic processes and void-conduit patterns depending on variations of the geological environments by presenting regional and cave-specific case studies. The cases include both well-known and newly recognized hypogene karst regions and caves of the world. They all focus on geological, hydrogeological, geodynamical and evolutionary contexts of hypogene speleogenesis. The last decade has witnessed the boost in recognition of the possibility, global occurrence, and practical importance of hypogene karstification (speleogenesis), i.e. the development of solutional porosity and permeability by upwelling flow, independent of recharge from the overlying or immediately adjacent surface. Hypogene karst has been identified and documented in many regions where it was previously overlooked or misinterpreted. The book enriches the basis for generalization and categorization of hypogene karst and thus improves our ability to adequately model hypogene karstification and predict related porosity and permeability. It is a book which benefits every researcher, student, and practitioner dealing with karst.