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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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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 gour is flowstone deposit, normally of calcite, built up along the edge of a pool due to precipitation from a thin film of overflow water. once initiated, by calcite-saturated water overflowing from floor hollows, development is selfenhancing, and the gours can grow into large dams many meters high and wide. inside the gour pool, more calcite may be precipitated as crystals or pearls. large flights of gours occur in many caves, with spectacular and well known examples around the hall of thirteen in the gouffre berger, france. large travertine, gours can form in the open air, as at band-i- amir, afghanistan [9]. see also rimstone barrage; rimstone barrier; rimstone dam.?

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Your search for eogenetic karst (Keyword) returned 28 results for the whole karstbase:
Showing 1 to 15 of 28
Conduit enlargement in an eogenetic karst aquifer, , Moore Paul J. , Martin Jonathan B. , Screaton Elizabeth J. , Neuhoff Philip S.

Most concepts of conduit development have focused on telogenetic karst aquifers, where low matrix permeability focuses flow and dissolution along joints, fractures, and bedding planes. However, conduits also exist in eogenetic karst aquifers, despite high matrix permeability which accounts for a significant component of flow. This study investigates dissolution within a 6-km long conduit system in the eogenetic Upper Floridan aquifer of north-central Florida that begins with a continuous source of allogenic recharge at the Santa Fe River Sink and discharges from a first-magnitude spring at the Santa Fe River Rise. Three sources of water to the conduit include the allogenic recharge, diffuse recharge through epikarst, and mineralized water upwelling from depth. Results of sampling and inverse modeling using PHREEQC suggest that dissolution within the conduit is episodic, occurring only during 30% of 16 sampling times between March 2003 and April 2007. During low flow conditions, carbonate saturated water flows from the matrix to the conduit, restricting contact between undersaturated allogenic water with the conduit wall. When gradients reverse during high flow conditions, undersaturated allogenic recharge enters the matrix. During these limited periods, estimates of dissolution within the conduit suggest wall retreat averages about 4 × 10−6 m/day, in agreement with upper estimates of maximum wall retreat for telogenetic karst. Because dissolution is episodic, time-averaged dissolution rates in the sink-rise system results in a wall retreat rate of about 7 × 10−7 m/day, which is at the lower end of wall retreat for telogenetic karst. Because of the high permeability matrix, conduits in eogenetic karst thus enlarge not just at the walls of fractures or pre-existing conduits such as those in telogenetic karst, but also may produce a friable halo surrounding the conduits that may be removed by additional mechanical processes. These observations stress the importance of matrix permeability in eogenetic karst and suggest new concepts may be necessary to describe how conduits develop within these porous rocks.


A conceptual view of carbonate island karst, 1999, Mylroie J. E. , Vacher H. L.
Conceptually, the karst of carbonate islands can be modeled as the result of eogenetic diagenesis, freshwater/ saltwater mixing, and glacioeustasyThe resulting eogenetic karst occurs in small, youthful limestone islands where the evolution of the karst is concurrent with meteoric diagenesis of the host rock, which has never been out of the active circulation of meteoric waterThe rearrangement of the material of high porosity / low permeability sediments into moderate porosity / high permeability rock feeds back to the nature of the diagenetic environment as the flow volume of the lens is reduced by increasing flow efficiencyLimestone islands are a constrained and simple environment, defined as carbonate islands (no noncarbonate rock) and composite islands (mixture of carbonate and non carbonate rock)Simple carbonate islands lack noncarbonate rocks within the active hydrological zone; carbonate-cover islands contain a noncarbonate contact that limits the freshwater lens and deflects vadose flowThe type of island greatly influences the subsequent karst hydrologyIncreasing island size appears to cross a threshold favoring conduit flowThe karst features resulting from these island types, combined with mixing geochemistry and glacioeustasy, differ from those in continental settings and require a unique conceptual approach to modeling

Eogenetic karst from the perspective of an equivalent porous medium., 2002, Vacher H. L. , Mylroie J. E.

Eogenetic karst from the perspective of an equivalent porous medium, 2002, Vacher H. L. , Mylroie J. E. ,
The porosity of young limestones experiencing meteoric diagenesis in the vicinity of their deposition (eogenetic karst) is mainly a double porosity consisting of touching-vug channels and preferred passageways lacing through a matrix of interparticle porosity. In contrast, the porosity of limestones experiencing subaerial erosion following burial diagenesis and uplift (telogenetic karst) is mainly a double porosity consisting of conduits within a network of fractures. The stark contrast between these two kinds of karst is illustrated by their position on a graph showing the hydraulic characteristics of an equivalent porous medium consisting of straight, cylindrical tubes (n-D space, where n is porosity, D is the diameter of the tubes, and log n is plotted against log D). Studies of the hydrology of small carbonate islands show that large-scale, horizontal hydraulic conductivity (K) increases by orders of magnitude during the evolution of eogenetic karst. Earlier petrologic studies have shown there is little if any change in the total porosity of the limestone during eogenetic diagenesis. The limestone of eogenetic karst, therefore, tracks horizontally in n-D space. In contrast, the path from initial sedimentary material to telogenetic karst comprises a descent on the graph with reduction of n during burial diagenesis, then a sideways shift with increasing D due to opening of fractures during uplift and exposure, and finally an increase in D and n during development of the conduits along the fractures. Eogenetic caves are mainly limited to boundaries between geologic units and hydrologic zones: stream caves at the contact between carbonates and underlying impermeable rocks (and collapse-origin caves derived therefrom); vertical caves along platform-margin fractures; epikarst; phreatic pockets (banana holes) along the water table; and flank margin caves that form as mixing chambers at the coastal freshwater-saltwater 'interface'. In contrast, the caverns of telogenetic karst are part of a system of interconnected conduits that drain an entire region. The eogenetic caves of small carbonate islands are, for the most part, not significantly involved in the drainage of the island

Syngenetic and eogenetic karst: an Australian viewpoint, 2002, Grimes K. G.

Eogenetic karst development on a small, tectonically active, carbonate island: Aguijan, Marina Islands, 2004, Stafford K. , Mylroie J, Taborosi D. , Jenson J.

Syngenetic Karst in Australia: a review, 2006, Grimes Ken G.
In syngenetic karst speleogenesis and lithogenesis are concurrent: caves and karst features are forming at the same time as the loose sediment is being cemented into a soft, porous rock. Eogenetic karst and soft-rock karst are closely related terms for features developed in soft, poorly-consolidated limestones. The distinctive features of syngenetic karst are: shallow horizontal cave systems; a general lack of directed conduits (low irregular chambers occur instead); clustering of caves at the margins of topographic highs or along the coast; paleosoil horizons; vertical solution pipes which locally form dense fields; extensive breakdown and subsidence to form collapse-dominated cave systems; a variety of surface and subsurface breccias and locally large collapse dolines and cenotes; and limited surface sculpturing (karren). These features are best developed in host sediments that have well developed primary matrix permeability and limited secondary cementation (and hence limited mechanical strength), for example dune calcarenites. Certain hydrological environments also assist: invading swamp waters or mixing at a well-developed watertable; or, near the coast, mixing at the top and bottom of a freshwater lens floating on salt water. Where these factors are absent the karst forms tend to be more akin to those of classical hard-rock or telogenetic karst.

Springflow hydrographs: Eogenetic vs. telogenetic karst, 2006, Florea Lj, Vacher Hl,
Matrix permeability in the range of 10(-11) to 10(-14) m(2) characterizes eogenetic karst, where limestones have not been deeply buried. In contrast, limestones of postburial, telogenetic karst have matrix permeabilities on the order of 10(-15) to 10(-20) m(2). Is this difference in matrix permeability paralleled by a difference in the behavior of springs draining eogenetic and telogenetic karst? Log Q/Q(min) flow duration curves from 11 eogenetic-karst springs in Florida and 12 telogenetic-karst springs in Missouri, Kentucky, and Switzerland, plot in different fields because of the disparate slopes of the curves. The substantially lower flow variability in eogenetic-karst springs, which results in the steeper slopes of their flow duration curves, also makes for a strong contrast in patterns (e.g., 'flashiness') between the eogenetic-karst and telogenetic-karst spring hydrographs. With respect to both spring hydrographs and the flow duration curves derived from them, the eogenetic-karst springs of Florida are more like basalt springs of Idaho than the telogenetic-karst springs of the study. From time-series analyses on discharge records for 31 springs and published time-series results for 28 additional sites spanning 11 countries, we conclude that (1) the ratio of maximum to mean (Q(max)/Q(mean)) discharge is less in springs of eogenetic karst than springs of telogenetic karst; (2) aquifer inertia (system memory) is larger in eogenetic karst; (3) eogenetic-karst aquifers take longer to respond to input signals; and (4) high-frequency events affect discharge less in eogenetic karst. All four of these results are consistent with the hypothesis that accessible storage is larger in eogenetic-karst aquifers than in telogenetic-karst aquifers

Syngenetic Karst in Australia: a review, 2006, Grimes, Ken G.

In syngenetic karst speleogenesis and lithogenesis are concurrent: caves and karst features are forming at the same time as the loose sediment is being cemented into a soft, porous rock. "Eogenetic karst" and "soft-rock karst" are closely related terms for features developed in soft, poorly-consolidated limestones. The distinctive features of syngenetic karst are: shallow horizontal cave systems; a general lack of directed conduits (low irregular chambers occur instead); clustering of caves at the margins of topographic highs or along the coast; paleosoil horizons; vertical solution pipes which locally form dense fields; extensive breakdown and subsidence to form collapse-dominated cave systems; a variety of surface and subsurface breccias and locally large collapse dolines and cenotes; and limited surface sculpturing (karren). These features are best developed in host sediments that have well developed primary matrix permeability and limited secondary cementation (and hence limited mechanical strength), for example dune calcarenites. Certain hydrological environments also assist: invading swamp waters or mixing at a well-developed watertable; or, near the coast, mixing at the top and bottom of a freshwater lens floating on salt water. Where these factors are absent the karst forms tend to be more akin to those of classical hard-rock or telogenetic karst.


Eogenetic karst, glacioeustatic cave-pools and anchihaline environments on Mallorca Island: a discussion of coastal speleogenesis., 2007, Gins Angel, Gins Joaqun
Coastal karst is characterized by special geomorphologic and hydrodynamic conditions as well as by peculiar sedimentary, geochemical, and biospeleological environments. Generally, the more distinctive karstic features produced near the coastline are strongly influenced by sea-level changes, which generate a broad set of interactions between littoral processes and karst development. The glacioeustatic rises and falls of sea level affected the littoral karst in different ways, namely: vertical and horizontal shifts in the shoreline position, changes in elevation of the local water table, and vertical displacements of the halocline. Most eogenetic karsts have been subjected over long time spans to repeated changes of a variety of vertically-zoned geochemical environments: vadose, phreatic meteoric-water, brackish mixing-waters and even marine water. Many coastal caves appear to be passively drowned by Holocene sea-level rise, and to contain glacioeustatic pools of varied size where the current water table intersects formerly air-filled chambers or passages. These coastal phreatic waters are controlled by sea level and fluctuate with tides. Significantly, features such as phreatic speleothems that are able to record ancient sea levels occur closely associated to the surface of the pools. The cave pools are brackish or even marine anchialine environments that contain remarkable communities of troglobitic stygofauna. All of these aspects can be studied in detail along the southern and eastern coast of Mallorca Island owing to the widespread outcrop of Upper Miocene calcarenites, in which the development of eogenetic karst features started approximately 6 Ma ago, at the end of Messinian times. Some outstanding coastal caves result and include the celebrated Coves del Drac (explored by E.A. Martel in 1896), the labyrinthine Cova des Pas de Vallgornera (more than 30 km in length) and the recently explored Cova de sa Gleda (whose submerged passages exceed 10 km, as shown by scuba-diving surveys). Careful observations and detailed mapping of caves in the Upper Miocene reef rocks of Mallorca permit a better understanding of the coastal speleogenetic processes involved in a typical eogenetic karst over time ranges greater than 1 Ma. The role played by recurrent glacioeustatic oscillations of sea level and the subsequent rises and falls of the water table are emphasized in our model. There are two associated mechanisms: the triggering of breakdown by the loss of buoyant support that follows each lowering of sea level (i.e., during glaciations or smaller cold events) and the later underwater solution of boulders and collapse debris (during high sea levels that correspond to interglacial events). Additionally, tidal fluctuations affecting groundwaters would enhance solutional enlargement of caves and vug-porosity connected to the sea, rather than conventional karstic flow through conduits that probably is not as important an agent in eogenetic speleogenesis.

Eogenetic karst, glacioeustatic cave pools and anchialine environments on Mallorca Island: a discussion of coastal speleogenesis, 2007, Gins Angel And Gins Joaquin
Coastal karst is characterized by special geomorphologic and hydrodynamic conditions as well as by peculiar sedimentary, geochemical, and biospeleological environments. Generally, the more distinctive karstic features produced near the coastline are strongly influenced by sea-level changes, which generate a broad set of interactions between littoral processes and karst development. The glacioeustatic rises and falls of sea level affected the littoral karst in different ways, namely: vertical and horizontal shifts in the shoreline position, changes in elevation of the local water table, and vertical displacements of the halocline. Most eogenetic karsts have been subjected over long time spans to repeated changes of a variety of vertically-zoned geochemical environments: vadose, phreatic meteoric-water, brackish mixing-waters and even marine water. Many coastal caves appear to be passively drowned by Holocene sea-level rise, and to contain glacioeustatic pools of varied size where the current water table intersects formerly air-filled chambers or passages. These coastal phreatic waters are controlled by sea level and fluctuate with tides. Significantly, features such as phreatic speleothems that are able to record ancient sea levels occur closely associated to the surface of the pools. The cave pools are brackish or even marine anchialine environments that contain remarkable communities of troglobitic stygofauna. All of these aspects can be studied in detail along the southern and eastern coast of Mallorca Island owing to the widespread outcrop of Upper Miocene calcarenites, in which the development of eogenetic karst features started approximately 6 Ma ago, at the end of Messinian times. Some outstanding coastal caves result and include the celebrated Coves del Drac (explored by E.A. Martel in 1896), the labyrinthine Cova des Pas de Vallgornera (more than 30 km in length) and the recently explored Cova de sa Gleda (whose submerged passages exceed 10 km, as shown by scuba-diving surveys). Careful observations and detailed mapping of caves in the Upper Miocene reef rocks of Mallorca permit a better understanding of the coastal speleogenetic processes involved in a typical eogenetic karst over time ranges greater than 1 Ma. The role played by recurrent glacioeustatic oscillations of sea level and the subsequent rises and falls of the water table are emphasized in our model. There are two associated mechanisms: the triggering of breakdown by the loss of buoyant support that follows each lowering of sea level (i.e., during glaciations or smaller cold events) and the later underwater solution of boulders and collapse debris (during high sea levels that correspond to interglacial events). Additionally, tidal fluctuations affecting groundwaters would enhance solutional enlargement of caves and vug-porosity connected to the sea, rather than conventional karstic flow through conduits that probably is not as important an agent in eogenetic speleogenesis.

Eogenetic karst, glacioeustatic cave pools and anchialine environments on Mallorca Island: a discussion of coastal speleogenesis, 2007, Gins A. , Gins J.

Coastal karst is characterized by special geomorphologic and hydrodynamic conditions as well as by peculiar sedimentary, geochemical, and biospeleological environments. Generally, the more distinctive karstic features produced near the coastline are strongly influenced by sea-level changes, which generate a broad set of interactions between littoral processes and karst development. The glacioeustatic rises and falls of sea level affected the littoral karst in different ways, namely: vertical and horizontal shifts in the shoreline position, changes in elevation of the local water table, and vertical displacements of the halocline. Most eogenetic karsts have been subjected over long time spans to repeated changes of a variety of vertically-zoned geochemical environments: vadose, phreatic meteoric-water, brackish mixing-waters and even marine water. Many coastal caves appear to be passively drowned by Holocene sea-level rise, and to contain glacioeustatic pools of varied size where the current water table intersects formerly air-filled chambers or passages. These coastal phreatic waters are controlled by sea level and fluctuate with tides. Significantly, features such as phreatic speleothems that are able to record ancient sea levels occur closely associated to the surface of the pools. The cave pools are brackish or even marine anchialine environments that contain remarkable communities of troglobitic stygofauna. All of these aspects can be studied in detail along the southern and eastern coast of Mallorca Island owing to the widespread outcrop of Upper Miocene calcarenites, in which the development of eogenetic karst features started approximately 6 Ma ago, at the end of Messinian times. Some outstanding coastal caves result and include the celebrated Coves del Drac (explored by E.A. Martel in 1896), the labyrinthine Cova des Pas de Vallgornera (more than 30 km in length) and the recently explored Cova de sa Gleda (whose submerged passages exceed 10 km, as shown by scuba-diving surveys). Careful observations and detailed mapping of caves in the Upper Miocene reef rocks of Mallorca permit a better understanding of the coastal speleogenetic processes involved in a typical eogenetic karst over time ranges greater than 1 Ma. The role played by recurrent glacioeustatic oscillations of sea level and the subsequent rises and falls of the water table are emphasized in our model. There are two associated mechanisms: the triggering of breakdown by the loss of buoyant support that follows each lowering of sea level (i.e., during glaciations or smaller cold events) and the later underwater solution of boulders and collapse debris (during high sea levels that correspond to interglacial events). Additionally, tidal fluctuations affecting groundwaters would enhance solutional enlargement of caves and vug-porosity connected to the sea, rather than conventional karstic flow through conduits that probably is not as important an agent in eogenetic speleogenesis.


HYPOGENE KARST AND SULFATE DIAGENESIS OF THE DELAWARE BASIN: SOUTHEASTERN NEW MEXICO AND FAR WEST TEXAS, PhD Thesis , 2008, Stafford, Kevin Wayne

Hypogene speleogenesis is widespread throughout the Delaware Basin region as evidenced by intrastratal dissolution, hypogenic caves and suites of diagenetic minerals. The world famous carbonate caves of the Capitan reef facies of the Guadalupe Mountains have long been associated with sulfuric acid processes and recently have been associated with semi-confined, hypogene dissolution. However, evaporite karst within Permian backreef and basin-filling facies has been traditionally associated with surficial, epigene processes. On the eastern edge of the Delaware Basin cavernous porosity associated with oil reservoirs in Permian carbonates have been attributed to eogenetic karst processes.
Interbedded (evaporite / carbonate), backreef facies within the mid-Permian Seven Rivers Formation exhibit characteristics of hypogene karst associated with semi-confined dissolution controlled by the eastward migration and entrenchment of the Pecos River. Coffee Cave is a good example of hypogene dissolution, forming a multi-storey, rectilinear maze with abundant distinctive morphologic feature suites (i.e. risers, channels and cupolas) indicative of hypogene speleogenesis. Other caves within the Seven Rivers and Rustler Formations show similar patterns, although often less well developed.
Within the Delaware Basin, Castile Formation evaporites have been extensively modified by hypogene processes. Field mapping coupled with GIS analyses clearly shows that karst development and evaporite calcitization are highly clustered throughout the outcrop area. Individual caves commonly exhibit complex morphologies, including complete suites of morphologic features indicative of intrastratal dissolution. Clusters of hypogene caves are commonly associated with clusters of evaporite calcitization and often occurrences of secondary selenite bodies, suggesting all three are genetically related. Brecciated cores and associated native sulfur deposits indicate that calcitized evaporites are the result of semi-confined sulfate reduction in the presence of ascending hydrocarbons. Hypogene caves are currently being overprinted by epigene processes as surface denudation results in breaching of previously confined solutional conduits. However, calcitized evaporites stand as resistant masses attesting to the widespread importance of hypogene processes within the Castile Formation.
On the southern end of the Central Basin Platform, the spatial distribution of cavernous porosity, secondary mineralization and abundant karst fabrics within the Yates Field carbonate strata provide convincing evidence that karst porosity, at least locally, within the San Andres and overlying Permian strata is the result of hypogene speleogenesis. Porosity development appears to have been enhanced by high geothermal gradients and the addition of sulfuric acid-rich fluids, reminiscent of the same processes that have been proposed for the extensive carbonate caves of the Guadalupe Mountains.
Recognition of the widespread occurrence of hypogene speleogenesis throughout the Delaware Basin region indicates that the regional diagenetic evolution has been significantly affected by confined fluid migration, including not only the development of porosity but also the emplacement of many secondary mineral deposits. Therefore, future natural resource management plans must consider the nature of hypogene karst in site evaluations throughout the region in order to better predict geohazards, potential groundwater contamination and characterize mineral resources.


NMR Imaging of Fluid Exchange between Macropores and Matrix in Eogenetic Karst, 2009, Florea L. J. , Cunningham K. J. , Altobelli S.

Sequential time-step images acquired using nuclear magnetic resonance (NMR) show the displacement of deuterated water (D2O) by fresh water within two limestone samples characterized by a porous and permeable limestone matrix of peloids and ooids. These samples were selected because they have a macropore system representative of some parts of the eogenetic karst limestone of the Biscayne Aquifer in southeastern Florida. The macroporosity, created by the trace fossil Ophiomorpha, is principally well connected and of centimeter scale. These macropores occur in broadly continuous stratiform zones that create preferential flow layers within the Hydrogeologic units of the Biscayne. This arrangement of porosity is important because in coastal areas, it could produce a preferential pathway for salt water intrusion. Two experiments were conducted in which samples saturated with D2O were placed in acrylic chambers filled with fresh water and examined with NMR. Results reveal a substantial flux of fresh water into the matrix porosity with a simultaneous loss of D2O. Specifically, we measured rates upward of 0.001 mL/h/g of sample in static conditions, and perhaps as great as 0.07 mL/h/g of sample when fresh water continuously flows past a sample at velocities less than those found within stressed areas of the Biscayne. These experiments illustrate how fresh water and D2O, with different chemical properties, migrate within one type of matrix porosity found in the Biscayne. Furthermore, these experiments are a comparative exercise in the displacement of sea water by fresh water in the matrix of a coastal, karst aquifer since D2O has a greater density than fresh water.


ON THE ROLE OF HYPOGENE SPELEOGENESIS IN SHAPING THE COASTAL ENDOKARST OF SOUTHERN MALLORCA (WESTERN MEDITERRANEAN), 2009, Gines J. , Gines A. , Fornos J. , Merino A. , Gracia F.

The Migjorn region is one of the main karst areas in the island of Mallorca (Balearic Archipelago, Western Mediterranean) and has abundant coastal caves developed in Upper Miocene reefal carbonate rocks. In general terms it is an eogenetic karst platform in which littoral mixing dissolution processes usually represent the most important speleogenetic mechanism to be considered. Nevertheless, recent explorations in Cova des Pas de Vallgornera (Llucmajor Municipality), that nowadays has development exceeding 59 km of passages, raise interesting questions about the genesis of this outstanding littoral cave. An artificial entrance located at about 500 m from the coast line gives access to a complex assemblage of chambers and galleries, partially drowned by brackish waters, whose spatial disposition and morphological characteristics are strongly conditioned by the internal architecture of the Upper Miocene reef. The inner part of the cave consists of an extensive network of galleries that contain morpho-sedimentary features pointing to the possible participation of hypogene speleogenesis in the excavation of the system. Solutional features related to rising flow are abundant, together with Mn- and Fe-rich deposits and some minerals not known up to the l present in other caves of the region. The hypogene speleogenesis mechanisms that may have acted in Cova des Pas de Vallgornera could be associated with the feeble geothermal anomalies existing currently in the Llucmajor platform, related to important SW-NE faults which delimit the Campos subsidence basin in the southern end of Mallorca Island. The genesis of the cave system seems to be a complex matter including, besides coastal mixing processes and epigenic meteoric recharge, the participation of hypogene speleogenesis in an eogenetic unconfined setting.


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