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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. ...

Did you know?

That marble is 1. metamorphosed and recrystallized carbonate rock that is generally capable of supporting cave development. for example much of the antro del corchia in italy and many caves in the south nordland area of norway have formed in marble [9]. 2. limestone recrystallized and hardened by heat and pressure. 3. commercially, any limestone that will take a high polish [10].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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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;
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Your search for miocene (Keyword) returned 229 results for the whole karstbase:
Showing 211 to 225 of 229
MACROSCOPIC DIAGENETIC CHANGES IN LATE MIOCENE SPELEOTHEMS, WESTERN DESERT, EGYPT, 2012, Pickford, Martin

Understanding the diagenesis of speleothems is important on account of the fact that such deposits are often used for determining palaeoclimate parameters and for estimating the ages of speleothem growth. Impressive speleothem deposition of Vallesian age occurred in an immense palaeokarst network in the Western Desert, Egypt, the age of formation being determined on the basis of mammalian biochronology (fossils found in spelean clastic deposits intercalated between speleothems). Many of the Egyptian speleothems have been pervasively recrystallised internally, but their outer surfaces are usually well preserved except in the formations which were buried in clastic deposits, in which case the entire speleothem can be recrystallised. The recrystallisation results in large crystals (up to 20 cm diameter) growing radially outwards from the centre of stalagmites and stalactites, or at right angles to the outer surface of flowstone deposits. It is clear that crystal growth occurred without change of volume. Although the recrystallisation of speleothems in the Western Desert of Egypt resulted in the development of unusually large calcite crystals, it does indicate that diagenesis may be an important process that needs to be taken into account before speleothems in other karst systems can be used as raw material for unravelling palaeoclimatic and geochronological parameters. The gross morphology of the Egyptian speleothems is described in order to put on record the effects of diagenesis on them. The geochemistry of the speleothems remains to be studied.


Carbon and oxygen isotopic composition of the Middle Miocene Badenian gypsum-associated limestones of West Ukraine, 2012, Peryt T. M. , Durakiewicz T. , Peryt D. , Poberezhskyy A.

The middle Miocene Badenian basin of the Carpathian Foredeep is characterized by complex sedimentary and diagenetic carbonate-evaporite transitions. Six locations have been selected to evaluate the controls on the carbonand oxygen isotopic composition of the Badenian gypsum-associated limestones of the Tyras Formation in WestUkraine. At three locations marine limestones overlie the gypsum, at one location (Anadoly) the gypsum-associatedlimestones are polygenic, and at two localities (Pyshchatyntsi and Lozyna) gypsum deposits are lacking. Thestudied limestones have originated as primary, mostly peloidal carbonates as well as secondary carbonates formed by hypogene sulphate calcitisation. They show a wide range of δ13C (from from -0.9‰ to -39.8‰) and δ18O values(from 0.9‰ to -12.2‰). The Badenian limestones formed in marine environments (either as deposits accumulatedat the bottom of the sea or forming the infillings of solution cavities within gypsum) have less negative δ18O values compared to predominantly diagenetic formations. Wide ranges and usually very negative δ13C values andlow δ18O values of those limestones indicate that they suffered important meteoric diagenesis as supported bycommon sparitic fabrics. In addition, a large range of δ13C values even in the group of samples characterized byless-negative δ18O values shows that bacterial sulphate reduction and methane oxidation were active processes inthe pore fluids of the Tyras Formation. Very low carbon isotopic compositions (δ13C values from -22 to -40‰) of some sparitic limestones in the studied sections indicate the occurrence of oxidized methane within the diagenetic environment. Accordingly, the isotopic signatures of the studied limestones are a combination of both primary and secondary processes, the latter having a primordial importance. The common occurrence of similar negative δ13Cand δ18O values in evaporite-related carbonates in other Miocene evaporite basins suggest that extensive dissolution-reprecipitation in diagenetic or vadose-phreatic environments were common in evaporite-related carbonates.


Carbon and oxygen isotopic composition of the Middle Miocene Badenian gypsum-associated limestones of West Ukraine, 2012, Peryt T. M. , Durakiewicz T. , Peryt D. , Poberezhskyy A.

The middle Miocene Badenian basin of the Carpathian Foredeep is characterized by complex sedimentary and diagenetic carbonate-evaporite transitions. Six locations have been selected to evaluate the controls on the carbonand oxygen isotopic composition of the Badenian gypsum-associated limestones of the Tyras Formation in WestUkraine. At three locations marine limestones overlie the gypsum, at one location (Anadoly) the gypsum-associatedlimestones are polygenic, and at two localities (Pyshchatyntsi and Lozyna) gypsum deposits are lacking. Thestudied limestones have originated as primary, mostly peloidal carbonates as well as secondary carbonates formed by hypogene sulphate calcitisation. They show a wide range of δ13C (from from -0.9‰ to -39.8‰) and δ18O values(from 0.9‰ to -12.2‰). The Badenian limestones formed in marine environments (either as deposits accumulatedat the bottom of the sea or forming the infillings of solution cavities within gypsum) have less negative δ18O values compared to predominantly diagenetic formations. Wide ranges and usually very negative δ13C values andlow δ18O values of those limestones indicate that they suffered important meteoric diagenesis as supported bycommon sparitic fabrics. In addition, a large range of δ13C values even in the group of samples characterized byless-negative δ18O values shows that bacterial sulphate reduction and methane oxidation were active processes inthe pore fluids of the Tyras Formation. Very low carbon isotopic compositions (δ13C values from -22 to -40‰) of some sparitic limestones in the studied sections indicate the occurrence of oxidized methane within the diagenetic environment. Accordingly, the isotopic signatures of the studied limestones are a combination of both primary and secondary processes, the latter having a primordial importance. The common occurrence of similar negative δ13Cand δ18O values in 


SPELEOGENESIS ALONG DEEP REGIONAL FAULTS BY ASCENDING WATERS: CASE STUDIES FROM SLOVAKIA AND CZECH REPUBLIC, 2012, Bella Pavel, Bosak Pavel

The most conspicuous six examples illustrating ascending (perascensum) speleogenesis linked with deep faults/fault systemswere selected from Slovakia and Czech Republic. In the past,the caves have been described as product of phreatic, epiphreaticand vadose speleogenesis related to the evolution of localwater courses and valley incision, and linked mostly with Pleistocenegeomorphic evolution. Our analysis illustrates severalcommon characteristics of caves: (1) they developed along or inclose vicinity of deep faults/fault zones, commonly of regionalimportance; (2) the groundwater ascended due to deep faults/fault systems mostly as results of deep regional circulation ofmeteoric waters from adjacent karst or nonkarst areas; (3) the3D mazes and labyrinths dominate in cave morphology; (4)speleogens (e.g., cupolas, slots, ceiling channels, spongework,rugged phreatic morphology especially along slots) indicateascending speleogenesis in deep phreatic to phreatic environments;(5) they exhibit poor relation to the present landscape;in some of them fluvial sediments are completely missing inspite of surface rivers/streams in the direct vicinity; (6) strongepiphreatic re-modelling is common in general (e.g., subhorizontalpassages arranged in cave levels, water-table flat ceilingsand notches) and related to the evolution of the recent landscape;(7) recharge structures and correlate surface precipitatesare poorly preserved or completely missing (denuded) on thepresent surface in spite of fact that recent recharges broadlyprecipitate travertines; (8) caves can be, and some of them are,substantially older than the recent landscape (Pliocene, Miocene),and (9) caves were formed in conditions of slow water ascent, which differentiate the process from faster vauclusianascending speleogenetical models. Any of described caves containsclear diagnostic features of real hypogene caves. There aremissing evidences that at least heated groundwaters took partduring speleogenesis of studied caves, nevertheless, somewhatincreased water temperature can be expected during speleogenesisat least in some of caves. Any of described caves cannotbe directly characterized as product of thermal waters or hydrothermalprocess (i.e. as real hyperkarst sensu Cigna 1978),therefore they do not represent hypogenic caves.


Development of a deep karst system within a transpressional structure of the Dolomites in north-east Italy, 2013, Sauro Francesco, Zampieri Dario, Filipponi Marco

The Piani Eterni karst system is one of the longest and deepest caves of Italy situated in the southern sector of the Dolomiti mountain range. The area where the cave was formed displays peculiar structural settings confined in a tectonic transpressive corridor between two regional thrusts (Belluno and Valsugana). During Miocene uplift of the range the inheritance of Mesozoic structures led to the formation of a deep and wide upward-branching flower (or palm tree) structure cutting the carbonate sequence and exposing the surrounding surface to karst processes after erosion. The relative lowering of the hydrologic base level, due both to the uplift of the area and then to the carving of deep glacial valleys in the Quaternary, allowed the formation of paleo-phreatic conduits at subsequently deeper levels, interconnected by vadose shafts and canyons.

This work gives a detailed tectonic interpretation of the transpressive structure and picks out the tectonic features most favorable to the karst development. A detailed statistical analysis of the distribution and orientation of the karst conduits was performed using 31 km of 3D surveys showing that the development of the cave was strictly guided by a few favorable surfaces of stratigraphic and tectonic origin. These features are known in the literature as inception horizons and tectonic inception features, respectively. Cave levels are usually related to lithologic favorable conditions associated with standings of the paleo-water table. Here we suggest that some tectonic surface geometries could have led to the opening of voids in the active tectonic phase leading to the formation of the original proto-conduit network. Different types of tectonic inception features identified in the cave were described in terms of geometry and kinematics. Tensional fractures, as well as fault plane undulations and flexural slip surfaces between beds, are described as the most favorable tectonic surfaces for the development of the conduits. Finally, we discuss why transpressional settings and related flower structures in soluble rocks can enhance the karst process allowing the formation of huge and deep karst systems.


Unusual polygenetic void and cave development in dolomitized Miocene chalks on Barbados, West Indies, 2013, Sumrall J. B. , Mylroie J. E. , Machel H. G.

Barbados provides an unusual case of polygenetic cave development within dolomitized chalks and marls of the Miocene Oceanics Group. These diagenetic processes are driven by a succession and interplay of tectonic uplift, fracturing, hypogene fluid injection, overprinting by mixing zone diagenesis, and mechanical and biological erosion in the current littoral zone. The significance of the voids and caves within the chalks on Barbados are: 1) these appear to be the first dissolution caves documented in dolomitized chalk, and 2) these features show a polygenetic origin documenting the diagenetic changes in lithology that allowed the development and preservation of these cave types.


NA JAVORCE CAVE A NEW DISCOVERY IN THE BOHEMIAN KARST (CZECH REPUBLIC): UNIQUE EXAMPLE OF RELATIONSHIPS BETWEEN HYDROTHERMAL AND COMMON KARSTIFICATION, 2013, Dragoun J. Ž, á, K K. Vejlupek J. Filippi M. Novotný, J. Dobeš, P.

 

The Na Javorce Cave is located in the Bohemian Karst, Czech Republic, near the Karlštejn castle, about 25 km SW of Prague. The cave was discovered as a result of extensive exploration including cave digging and widely employed capping of narrow sections. Exploration in the cave has already lasted 20 years. The cave is fitted with several hundred meters of fixed and rope ladders and several small fixed bridges across intra-cave chasms. Access to the remote parts of the cave is difficult because of long narrow crawl passages and deep and narrow vertical sections. The Na Javorce Cave became the deepest cave discovered to date in Bohemia with the discovery of its deepest part containing a lake in 2010. The cave was formed in vertically dipping layers of Lower Devonian limestone; it is 1,723 m long and 129 m deep, of which 9 m is permanently flooded (data as of December 2012). The cave is polygenetic, with several clearly separable evolutionary stages. Cavities discovered to date were mostly formed along the tectonic structures of two main systems. One of these systems is represented by vertical faults of generally N-S strike, which are frequently accompanied by vein hydrothermal calcite with crystal cavities. The second fault system is represented by moderately inclined faults (dip 27 to 45°, dip direction to the W). Smaller tube-like passages of phreatic morphology connect the larger cavities developed along the two above-mentioned systems. The fluid inclusion data obtained for calcite developed along both fault systems in combination with C and O stable isotope studies indicate that the hydrothermal calcite was deposited from moderately saline fluids (0.5 to 8.7 wt. % NaCl equiv.) in the temperature range from 58 to 98 °C. The fluids were NaCl-type basinal fluids, probably derived from the deeper clastic horizons of the Barrandian sedimentary sequence. The age of the hydrothermal processes is unknown; geologically it is delimited by the Permian and Paleogene. The hydrothermal cavities are small compared to cavities formed during the later stages of karstification. The majority of the known cavities were probably formed by corrosion by floodwater derived from an adjacent river. This process was initiated during the Late Oligocene to Early Miocene, as was confirmed by typical assemblage of heavy minerals identical in the surface river sediments and in clastic cave sediments. The morphology of most cavities is phreatic or epiphreatic, with only local development of leveled roof sections (“Laugdecken”). The phreatic evolution of the cave is probably continuing into the present in its deepest permanently flooded part, which exhibits a water level close to that of the adjacent Berounka River. Nevertheless, the chemistry of the cave lake differs from that of the river water. The cave hosts all the usual types of cave decoration (including locally abundant erratics). The most interesting speleothem type is cryogenic cave carbonate, which was formed during freezing of water in relation to the presence of permafrost during the Glacial period. The occurrence of cryogenic cave carbonate here indicates that the permafrost of the Last Glacial period penetrated to a depth of at least 65 m below the surface.


Geochemistry and isotope geochemistry of the Monfalcone thermal waters (northern Italy): inference on the deep geothermal reservoir, 2013, Petrini R. , Italiano F. , Ponton M. , Slejko F. F. , Aviani U. , Zini L.

Geochemical investigations were carried out to define the origin of the low- to moderate-temperature thermal waters feeding the Monfalcone springs in northern Italy. Chemical data indicate that waters approach the composition of seawater. Mixing processes with cold low-salinity waters are highlighted. The δ18O and δD values are in the range −5.0 to −6.4 ‰, and −33 to −40 ‰, respectively, suggesting the dilution of the saline reservoir by karst-type freshwaters. A surplus of Ca2+ and Sr2+ ions with respect to a conservative mixing is ascribed to diagenetic reactions of the thermal waters with Cretaceous carbonates at depth. The measured Sr isotopic composition (87Sr/86Sr ratio) ranges between 0.70803 and 0.70814; after correction for the surplus Sr, a 87Sr/86Sr ratio indicating Miocene paleo-seawater is obtained. The dissolved gases indicate long-lasting gas–water interactions with a deep-originated gas phase of crustal origin, dominated by CO2 and marked by a water TDIC isotopic composition in the range −5.9 to−8.8 and helium signature with 0.08 < R/Ra < 0.27, which is a typical range for the crust. A possible scenario for the Monfalcone thermal reservoir consists of Miocene marine paleowaters which infiltrated through the karstic voids formed within the prevalently Cretaceous carbonates during the upper Eocene emersion of the platform, and which were entrapped by the progressive burial by terrigenous sediments.


THE LATE MIOCENE MINERALIZED HYPOGENE KARST AT BARE MOUNTAIN, SOUTHERN NEVADA, USA, 2013, Dublyansky Yuri, Sptl Christoph

Bare Mountain is an isolated complex of mountain peaks Southeast of the town of Beatty in southern Nevada. This small mountain range is located between the alluvial basins of Crater Flat to the East and the northern Amargosa Desert to the Southwest. The range is built of a folded and complexly faulted, generally northward-dipping sequence of weakly to moderately metamorphosed upper Proterozoic and Paleozoic marine rocks. Along the eastern and northern margins of Bare Mountain there are four clusters of Ag-Hg-fluorite deposits from which pipe-like breccia bodies have been reported in the literature. One of these deposits, the Diamond Queen Mine (aka Goldspar Mine; 36°50.4’ N, 116°38.3’ W) was prospected for gold and mined for fluorspar. The age of the mineralization is younger than 12.9±0.4 Ma (according to K/Ar dates of replacement adularia). During our visit in 2010 we observed solutional cavities in the open-pit works of the mine carved in the dolomite of the Cambrian Nopah Formation. The cavities have dimensions of a few meters to tens of meters. Their inner surfaces are smooth and barren. The morphology of the cavities strongly suggests dissolution under phreatic conditions. Cavities are filled with buff-colored clay material containing bands of black to dark-violet to yellow- green to colorless fluorite. Fluid inclusions in the Diamond Queen fluorite yielded homogenization temperatures of ca. 130°C. We measured the δD of the fluid inclusion water in this fluorite and compared them to δD values measured in scalenohedral calcite from the Sterling Mine (Au) located 1.5 km to the north. Isotopic values are remarkably similar: δD = -100±2 ‰ (n = 6). Despite the fact that the analyzed water was derived from hypogene, hydrothermal minerals these isotopic values bear a paleoclimatological significance. This is because according to the currently accepted model, the Au-Hg-fluorite deposits at Bare Mountain owe their existence to the circulation of meteoric water triggered by emplacement of the silicic magma chamber under the Timber Mountain-Oasis Valley caldera some 15 km to the north. The Late Miocene meteoric- hydrothermal water is isotopically similar to the modern-day precipitation (-106 to -92 ‰). Between ca. 1.5 and 2.5 Ma the δD values of meteoric water in the area were substantially less negative (-70 to -50 ‰) and then gradually decreased to modern values. Knowledge regarding hypogene karst associated with the epithermal ore deposits in Nevada is limited. In north-central Nevada, post-ore hypogene dissolution, brecciation and mineralization occurred at some of the Carlin Trend deposits at ca. 2 Ma. In contrast, hypogene karst was a preore process at Diamond Queen; it has played a role in creating the ore-bearing structure.


Hypogenic Karstification and Conduit System Controlling by Tectonic Pattern in Foundation Rocks of the Salman Farsi Dam in South-Western Iran, 2013, Koleini M. , Van Rooy J. L. , Bumby A.

The Salman Farsi dam project is constructed on the Ghareh Agahaj River about 140km south of Shiraz city in the Zagros Mountains of southwestern Iran. This tectonic province of southwestern Iran is characterized by a simple folded sedimentary sequence. The dam foundation rocks compose of the Asmari Formation of Oligo-miocene and generally comprise of a variety of karstified carbonate rocks varying from strong to weak rocks. Most of the rocks exposed at the dam site show a primary porosity due to incomplete diagenetic recrystallization and compaction. In addition to these primary dispositions to weathering, layering conditions (frequency and orientation of bedding) and the subvertical tectonic discontinuities channeled preferably the infiltrating by deep-sited hydrothermal solutions. Consequently the porosity results to be enlarged by dissolution and the rocks are expected to be karstified and to develop cavities in correspondence of bedding, major joint planes and fault zones. This kind of karsts is named hypogenic karsts which associated to the ascendant warm solutions. Field observations indicate strong karstification and vuggy intercalations especially in the middle part of the Asmari succession. The biggest karst in the dam axis which identified by speleological investigations is Golshany Cave with volume of about 150,000 m3. The tendency of the Asmari limestone for strong dissolution can alert about the seepage from the reservoir and area of the dam locality


Hypogenic Karstification and Conduit System Controlling by Tectonic Pattern in Foundation Rocks of the Salman Farsi Dam in South-Western Iran, 2013, Koleini Mehran, Van Rooy Jan Louis, Bumby Adam

The Salman Farsi dam project is constructed on the Ghareh Agahaj River about 140km south of Shiraz city in the Zagros Mountains of southwestern Iran. This tectonic province of southwestern Iran is characterized by a simple folded sedimentary sequence. The dam foundation rocks compose of the Asmari Formation of Oligo-miocene and generally comprise of a variety of karstified carbonate rocks varying from strong to weak rocks. Most of the rocks exposed at the dam site show a primary porosity due to incomplete diagenetic recrystallization and compaction. In addition to these primary dispositions to weathering, layering conditions (frequency and orientation of bedding) and the subvertical tectonic discontinuities channeled preferably the infiltrating by deep-sited hydrothermal solutions. Consequently the porosity results to be enlarged by dissolution and the rocks are expected to be karstified and to develop cavities in correspondence of bedding, major joint planes and fault zones. This kind of karsts is named hypogenic karsts which associated to the ascendant warm solutions. Field observations indicate strong karstification and vuggy intercalations especially in the middle part of the Asmari succession. The biggest karst in the dam axis which identified by speleological investigations is Golshany Cave with volume of about 150,000 m3. The tendency of the Asmari limestone for strong dissolution can alert about the seepage from the reservoir and area of the dam locality.


PALEOKARST SHAFTS IN THE WESTERN DESERT OF EGYPT: A UNIQUE LANDSCAPE, 2013, Mostafa, Ashraf

The Eocene limestone plateau of the western Desert of Egypt has various karst features, including shafts created during ancient wet periods. These Paleokarst shafts have been investigated on the plateau to the west of the Nile valley, specifically northwest of Assiut. Most of these shafts are infilled by conglomerate (cemented flint, red soil and limestone chips) and appear as pockets in limestone hills. The morphology of the shafts and the characteristics of their infillings suggest that they developed in vadose zone at the base of epikarst limits. This stage probably took place from the end of Early Eocene to the Middle Miocene. A later, different stage of water erosion occurred, most probably during Pliocene/Pleistocene period. This stage led to remove the epikarst zone, and reshaped the area to create a hilly landscape penetrated by infilled shafts.


Hypogenic Karstification and Conduit System Controlling by Tectonic Pattern in Foundation Rocks of the Salman Farsi Dam in South-Western Iran, 2013, Koleini M. , Louis J. , Rooy V. , Bumby A.

The Salman Farsi dam project is constructed on the Ghareh Agahaj River about 140km south of Shiraz city in the Zagros Mountains of southwestern Iran. This tectonic province of southwestern Iran is characterized by a simple folded sedimentary sequence. The dam foundation rocks compose of the Asmari Formation of Oligo-miocene and generally comprise of a variety of karstified carbonate rocks varying from strong to weak rocks. Most of the rocks exposed at the dam site show a primary porosity due to incomplete diagenetic recrystallization and compaction. In addition to these primary dispositions to weathering, layering conditions (frequency and orientation of bedding) and the subvertical tectonic discontinuities channeled preferably the infiltrating by deep-sited hydrothermal solutions. Consequently the porosity results to be enlarged by dissolution and the rocks are expected to be karstified and to develop cavities in correspondence of bedding, major joint planes and fault zones. This kind of karsts is named hypogenic karsts which associated to the ascendant warm solutions. Field observations indicate strong karstification and vuggy intercalations especially in the middle part of the Asmari succession. The biggest karst in the dam axis which identified by speleological investigations is Golshany Cave with volume of about 150,000 m3. The tendency of the Asmari limestone for strong dissolution can alert about the seepage from the reservoir and area of the dam locality


RESERVOIR CHARACTERISTICS OF THE COMPLEX KARST OF THE LLUCMAJOR PLATFORM, MALLORCA ISLAND (SPAIN): TOOL FOR HYDROCARBON RESERVOIR APPRAISAL, 2014, Lapointe, P. A.

The development of porosity in carbonate platforms takes many forms. Dissolution porosity as a result of karst processes is unique as it produces organized porosity and permeability over a variety of scales, and can do so in very short periods of time, geologically speaking. Karst developed in the Miocene formations of the Mallorca Island exhibits a complexity that seems to be very similar to the Kashagan or Aktote (Kazakhstan) or Kharyaga (CIS) karst reservoirs architecture characterized by different phases of island karst (mixing water) type with caves of different sizes and sponge karst, reworked and partly filled by paleosoils related to plateau karst developed during major sea level drops and finally hydro- (geo)-thermal processes. The Miocene rocks of the Llucmajor platform in the southwest of Mallorca island exhibit the three main types of karst developments that occurred through time, linked or not to glacio-eustatic changes: -1 Island karst (the flank-margin model); -2 Meteoric karst; -3 Hydrothermal karst/ These developments allow defining the so-called Complex Karst. Each of the terms is identified by specific overprints found in drilled wells (logs and cores) or on outcrops. The outcrops and subcrops of Mallorca Island represent an excellent analogue for understanding the complexity of the past carbonate platforms which are hydrocarbon targets for the industry


Geologic constraints and speleogenesis of Cova des Pas de Vallgornera, a complex coastal cave from Mallorca Island (Western Mediterranean), 2014, Ginés J. , Fornós J. J. , Ginés A. , Merino A. , Gràcia F.

The flat areas of eastern and southern Mallorca host a remarkable coastal karst, where Cova des Pas de Vallgornera stands out due to its length (more than 74 km) and its special morphological suite. The pattern of the cave is quite heterogeneous showing sharp differences produced by the architecture of the Upper Miocene reef: spongework mazes and collapse chambers dominate in the reef front facies, whereas joint-guided conduits are the rule in the back reef carbonates. Regarding the speleogenesis of the system, a complex situation is envisaged involving three main agents: coastal mixing dissolution, drainage of meteoric diffuse recharge, and hypogene basal recharge related to local geothermal phenomena. The cave system is disposed in two main tiers of passages, of which geomorphologic interpretations are derived from their elevation data. The evolutionary trends as well as the chronology of the different cave sections are difficult to establish owing to the frequent shifting of the coastal base level during the Plio-Quaternary. In this respect, the genesis and evolution of the cave were fully controlled by sea-level fluctuations in the Western Mediterranean basin, with the main phases of cave formation, based on vertebrate paleontological data, going back to mid-Pliocene times.


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