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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 natural tunnel is a nearly horizontal cave open at both ends, generally fairly straight in direction and fairly uniform in cross section [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 vein (Keyword) returned 56 results for the whole karstbase:
Showing 16 to 30 of 56
Brittle tectonics and major dextral strike-slip zone in the Buda karst (Budapest, Hungary), 1999, Benkovics L, Obert D, Bergerat F, Mansy Jl, Dubois M,
Three large (kilometric-scale) caves were studied in the Buda hills and the main directions of cave corridors, fault planes and mineralized veins were measured. Different stages of mineralizations are recognised: calcite scaleno-hedrons, baryte, silica, gypsum. New investigations of fluid inclusions in the baryte suggest a crystallization temperature of 50 degrees C and a freshwater fluid source. Microtectonic analysis allows the reconstruction of the successive tectonic events: (1) a NE-SW extensional phase at the Late Eocene-Early Oligocene limit (phase I), (2) a strike-slip phase with NW-SE compression and NE-SW extension during the Late Oligocene-Early Miocene (phase II), (3) a NW-SE transtensional phase (phase III) and finally (4) a NE-SW extensional phase of Quaternary age (phase IV). The major phase is the strike-slip one, characterized by an important dextral strike-slip zone: the Ferenc-hegy zone. (C) Elsevier, Paris

Hydrotermalni puvod jeskyni v Ceskem krasu: nove paradigma, 1999, Suchy V. , Zeman A.

The caves developed in Lower Paleozoic carbonate rocks of the Bohemian Karst are interpreted as a result of a hydrothermal dissolution. The main evidence includes 1) a close spatial link of the caves to hydrothermal calcite veins, 2) a variety of distinctive dissolution forms indicative of non-gravitational hydrodynamics, and 3) presence of specific, exotic precipitates within the caves. Moreover, most of the features typical of the caves of the Bohemian Karst can be readily compared to those of the Zbrasov Caves of Moravia that have been known for long as a typical example of hydrothermal caves. The origin of at least some hydrothermal caves in the Bohemian Karst and elsewhere in the Czech Republic could have been tied to the circulation of warm fluids along active tectonic lineaments. A line of indirect evidence indicates that in the Bohemian Massif, transient pulses of fluid activity that were responsible for the origin of hydrothermal caves may have occurred since Tertiary period.

Karst processes along a major seismotectonic zone: an example from the Bohemian Massif, Czech Republic, 1999, Suchy V. , Zeman A.

Fluid movements along major north-south-trendingseismotectonic zones were responsible for the development of hydrothermal caves in limestones of the Bohemiankarst and elsewhere in the Bohemian Massif, Czech Republic. Many caves and caverns are closelylinked to hydrothermal calcite veins and reveal characteristiccupola-form cavities and exotic internal precipitates.A possible role of sulphuric acid speleogenesis in the origin of the caves is also discussed

Vein Cavities in the Castleton caves - Further information, 2000, Cordingley J.

Vein cavities; An early stage in the evolution of the Castleton caves, Derbyshire, 2000, Ford T. D.

Vein and Karst Barite Deposits in the Western Jebilet of Morocco: Fluid Inclusion and Isotope (S, O, Sr) Evidence for Regional Fluid Mixing Related to Central Atlantic Rifting, 2000, Valenza Katia, Moritz Robert, Mouttaqi Abdellah, Fontignie Denis, Sharp Zachary,
Numerous vein and karst barite deposits are hosted by Hercynian basement and Triassic rocks of the western Jebilet in Morocco. Sulfur, oxygen, and strontium isotope analyses of barite, combined with fluid inclusion microthermometry on barite, quartz, and calcite were used to reveal the nature and source of the ore-forming fluids and constrain the age of mineralization. The{delta} 34S values of barite between 8.9 and 14.7 per mil are intermediate between the sulfur isotope signatures of Triassic evaporites and Triassic-Jurassic seawater and lighter [IMG]f1.gif' BORDER='0'>, probably derived from the oxidation of dissolved H2S and leaching of sulfides in the Hercynian basement. The 87Sr/86Sr ratios of barite between 0.7093 and 0.7130 range between the radiogenic strontium isotope compositions of micaceous shale and sandstone and the nonradiogenic isotopic signature of Triassic to Jurassic seawater and Cambrian limestone. The{delta} 18O values of barite between 11 and 15 per mil (SMOW) support mixing between two or more fluids, including Late Triassic to Jurassic seawater or a water dissolving Triassic evaporites along its flow path, hot basinal, or metamorphic fluids with{delta} 18O values higher than 0 per mil and/or meteoric fluids with{delta} 18O values lower than 0 per mil. The general trend of decreasing homogenization temperatures and initial ice melting temperatures with increasing salinities of H2O-NaCl {} CaCl2 fluid inclusions trapped in barite, quartz, and calcite indicates that a deep and hot basinal fluid with salinities lower than 6 wt percent NaCl equiv might have mixed with a cooler surficial solution with a mean salinity of 20 wt percent NaCl equiv. Calcium was leached from the Cambrian limestone and the clastic and mafic volcanic rocks of the Hercynian basement. Alkali feldspars and micas contained in the Cambrain sandstones provided most of the Ba to the hydrothermal system. Vein and karst deposits are modeled as a two-component mixing process in which the temperature and the S and Sr isotope composition of the end members changed during the 220 to 155 Ma interval. The hot basinal fluid remained volumetrically dominant during the entire mineralization process. Differences in mean S, O, and Sr isotope compositions among the barite families are interpreted as reflecting differences in mineralization age. Most barite deposits formed before the Kimmeridgian, except for north-south-oriented vein barite, karst barite, and barite cement in the conglomeratic Upper Jurassic, which were deposited later, possibly around 155 Ma. Similar genetic processes have been described for late Paleozoic to Mesozoic F-Ba vein deposits in western Europe. The vein and karst barite in the western Jebilet of Morocco reveals a wide-scale regional mineralization event related to Central Atlantic rifting

The role of evaporites in the genesis of base metal sulphide mineralisation in the Northern Platform of the Pan-African Damara Belt, Namibia: geochemical and fluid inclusion evidence from carbonate wa, 2000, Chetty D, Frimmel He,
The Otavi Mountain Land is a base metal sulphide ore province in northern Namibia where deposits are hosted by platform carbonates of the Otavi Group in a foreland fold-and-thrust belt on the northern edge of the Pan-African Damara Belt. Deposits have been classified as the Berg Aukas- or Tsumeb-types, based on differences in ore association? stratigraphic position and geochemistry of ores and gangue carbonates. Mineralisation at these deposits is accompanied by carbonate alteration in the form of dolomite and calcite veins, carbonate recrystallisation, calcitisation and carbonate silicification. Based on cathodoluminescence imaging, trace and rare earth element (REE), O and C isotope, and fluid inclusion data, a series of carbonate generations, constituting wall rock alteration around the Tsumeb and Kombat (Tsumeb-type) and Berg Aukas (Berg Aukas-type) deposits, was established. Similar data obtained on the recently discovered Khusib Springs deposit indicate a strong affinity to Tsumeb-type deposits. Tsumeb-type deposits are distinguished from Berg Aukas-type deposits by having trace element and REE concentrations that are significantly higher in the alteration products compared to the carbonate host rocks. Only around Tsumeb-type deposits a relative enrichment in light REE is noted for the hydrothermal carbonate generations that are cogenetic with the main stage of mineralisation. Microthermometric results from fluid inclusions in carbonate alteration phases and associated quartz indicate relatively high salinity (17-33 wt% NaCl equivalent) for the main mineralising and subsequent sulphide remobilisation stages at the deposits investigated. Estimated mineralisation temperatures are significantly higher for Tsumeb-type deposits (370-405 degrees C) with early sulphide remobilisation in Tsumeb at 275 degrees C, whereas they are lower at Berg Aukas (up to 255 degrees C). Fluid inclusion leachate analysis suggests that most of the observed salinity can be ascribed to dissolved, predominantly Ca- and Mg-carbonates and chlorides with subordinate NaCl. Na-Cl-Br leachate systematics indicate a derivation of the fluid salinity from the interaction with evaporitic rocks en route. Tsumeb-type mineralisation is interpreted to be derived from fluids expelled during Pan-African orogeny in the more intensely deformed internal zones of the Damara Belt further south. When the high salinity fluids reached the carbonate platform after having scavenged high concentrations of base metals, base metal sulphide precipitation occurred in zones of high porosity, provided by karst features in the carbonate sequence. Results obtained for the Berg Aukas-type deposits emphasise their derivation from basinal brines, similar to Mississippi Valley-type deposits, and confirm that mineralisation of the Berg Aukas- and Tsumeb-types are both spatially and temporally distinct

Speleogenesis of the Black Hills Maze Caves, South Dakota, USA, 2000, Palmer A. N. , Palmer M. V.
Caves of the Black Hills of South Dakota, USA, are located in the Madison Limestone of Mississippian (early Carboniferous) age in a zone of diagenetic breccias and late-Mississippian paleokarst. Most of the caves are extremely complex networks with multiple stratigraphically controlled storeys. Today they are essentially hydrologic relics. Their history is as complex as the caves themselves: (1) The earliest cave openings were formed by diagenetic processes, mainly by the dissolution and reduction of sulfates. Oxidation of hydrogen sulfide produced many small and rather isolated voids lined by brecciated bedrock. (2) Late Mississippian exposure produced caves, dolines, and surface fissures, which were later filled with basal Pennsylvanian (late Carboniferous) sands and clays of the Minnelusa Formation. (3) Deposition of sedimentary strata buried these early karst features to depths of at least two kilometers. During this time, voids that had not been entirely filled by Pennsylvanian sediment were lined by a thin layer of scalenohedral calcite, and later by quartz. (4) Uplift of the Black Hills at the end of the Cretaceous Period exposed the Madison Limestone once again, allowing rapid groundwater flow through it. The earlier caves and solution pockets were enlarged at this time. (5) A thick layer of rhombohedral calcite precipitated on the cave walls, probably as the result of stagnation of groundwater caused by late Tertiary aggradation, which blocked spring openings. (6) Both before and after the calcite wall crust was deposited, deep subaerial weathering produced boxwork, with veins of calcite that had replaced earlier sulfates, as well as thick accumulations of carbonate sediment. The Tertiary cave enlargement probably involved mixing of at least two of the following water sources: artesian flow from recharge along the carbonate outcrop area, diffuse recharge through the overlying sandstone, and rising thermal water. There is evidence for all three sources, but the relative importance of each is still uncertain.

Gypsum-karst collapse in the Black Hills, South Dakota-Wyoming, USA, 2000, Epstein, Jack B.

Intrastratal dissolution of gypsum and anhydrite in four stratigraphic units of Pennsylvanian to Jurassic age in the Black Hills of South Dakota and Wyoming has resulted in many collapse features that have developed primarily in the non-soluble overlying rocks. Subsidence has affected several areas that are undergoing urban development. Subsurface intrastratal dissolution of anhydrite in the Minnelusa Formation has produced a regional collapse breccia, extensive disruption of bedding, many dolines, and breccia pipes and pinnacles, some of which extend upwards more than 300 m into overlying strata. Recent collapse is evidenced by steep-walled dolines more than 20 m deep, collapse in water wells and natural springs resulting in sediment disruption and contamination, and fresh circular scarps surrounding shallow depressions. Many beds of gypsum are contorted because of expansion due to its hydration from anhydrite, and many gypsum veinlets extend downward along random fractures from parent gypsum beds. Several dolines are sites of resurgent springs. As the anhydrite dissolution front in the subsurface Minnelusa moves downdip and radially away from the center of the Black Hills uplift, these resurgent springs will dry up and new ones will form as the geomorphology of the Black Hills evolves. Old dolines and breccia pipes, preserved in cross section on canyon walls, attest to the former position of the dissolution front. Mirror Lake, which is expanding northwestward in a downdip direction, is a local analog of a migrating dissolution front.

Geochemical study of calcite veins in the Silurian and Devonian of the Barrandian Basin (Czech Republic): evidence for widespread post-Variscan fluid flow in the central part of the Bohemian Massif, 2000, Suchy V. , Heijlen W. , Sykorova I. , Muchez Ph. , Dobes P. , Hladikova J. , Jackova I. , Safanda J. , Zeman A.

Carbonate fracture cements in limestones have been investigated by fluid inclusion and stable isotope analysis to provide insight into fluid evolution and deformation conditions of the Barrandian Basin (Silurian–Devonian) of the Czech Republic. The fractures strike generally north–south and appear to postdate major Variscan deformation. The most common fracture cement is calcite that is locally accompanied by quartz, natural bitumen, dolomite, Mn-oxides and fluorite. Three successive generations of fracture-filling calcite cements are distinguished based on their petrographical and geochemical characteristics. The oldest calcite cements (Stage 1) are moderate to dull brown cathodoluminescent, Fe-rich and exhibit intense cleavage, subgrain development and other features characteristic of tectonic deformation. Less tectonically deformed, variable luminescent Fe-poor calcite corresponds to a paragenetically younger Stage 2 cement. First melting temperatures, Te, of two-phase aqueous inclusions in Stages 1 and 2 calcites are often around 2208C, suggesting that precipitation of the cements occurred from H2O–NaCl fluids. The melting temperature, Tm, has values between 0 and 25.88C, corresponding to a low salinity between 0 and 8.9 eq. wt% NaCl. Homogenization temperatures, Th, from calcite cements are interpreted to indicate precipitation at about 708C or less. No distinction could be made between the calcite of Stages 1 and 2 based on their fluid inclusion characteristics. In some Stage 2 cements, inclusions of highly saline (up to 23 eq. wt% NaCl) brines appear to coexist with low-salinity inclusions. The low salinity fluid possibly contains Na-, K-, Mg- and Ca-chlorides. The high salinity fluid has a H2O–NaCl–CaCl2 composition. Blue-to-yellow-green fluorescing hydrocarbon inclusions composed of medium to higher API gravity oils are also identified in some Stages 1 and 2 calcite cements. Stage 1 and 2 calcites have d 18O values between 213.2‰ and 27.2‰ PDB. The lower range of the calculated d 18O values of the ambient fluids (23.5‰ to 1 2.7‰ SMOW) indicate precipitation of these cements from deeply circulating meteoric waters. The presence of petroleum hydrocarbon inclusions in some samples is interpreted to reflect partial mixing with deeper basinal fluids. The paragenetically youngest Stage 3 calcite cement has only been encountered in a fewveins.These calcites are characterised by an intensely zoned luminescence pattern, with bright yellow and non-luminescent zones. Inclusions of Mn-oxides and siliceous sinters are commonly associated with Stage 3 calcite, which is interpreted to have precipitated from shallower meteoric waters. Regional structural analysis revealed that the calcite veins of the Barrandian basin belong to a large-scale system of north–south-trending lineaments that run through the territory of the Czech Republic. The veins probably reflect episodes of fluid migration that occurred along these lineaments during late stages of the Variscan orogeny

Evolution of river network at the 'Cevennes-Grands Causses' transition: Consequences for the evaluation of uplift, 2001, Camus H,
The Mediterranean catchment of the Cevennes (S. France) presents deep incision of the river network (fig. 1 and 2). Combined geomorphology and analyses of the residual sedimentary formations allows to reconstruct a complex history of river network evolution, including capture of tributaries of the Herault River (fig. 1, 2 and 3). The history of uplift of the upstream drainage area could be estimated from the provenance studies of the fluvial and karstic deposits, however river incision is also controlled sea-level changes and differential erosion, which makes reconstruction more complex. Allochthonous clasts types Analyses of allochtonous deposits on the Grands Causses surface reveals different origin for sediments from the hill top and the Airoles valley (fig. 4b), which was previously unrecognised. Facies 1 is found on the highest points of the Grands Causses surface (well sorted rounded quartz pebbles in red shale matrix) it corresponds to a weathered residual sediments (dismantling of an ancient cover). Facies 2 is found on the slope of the Airoles Valley (fig. 7). It consists of alluvial crystalline poorly sorted clasts with outsized clasts (up to 50cm) of quartz-vein, schists in a matrix of shales and sand (weathered granite). Between the hill tops and the Airoles Valley, karstic network presents a sediment fill with clasts reworked from facies I and facies 2 (fig. 6). Airoles valley model : an example of diachronic formation of drainage network The Airoles dry valley stretches on the Grands Causses from the north (700 m) to the south into the present thalweg line of the Vis canyon (500 m) (fig. 1b & 3). Crystalline deposits witness an ancient catchment in the Cevennes. Presently, the catchment in the crystalline basement is disconnected and captured by the Arre River flowing eastwards (fig. 3 & 4a). The profile of the Airoles abandoned valley connects with the present Vis Canyon, therefore, at the time of capture, incision of the Vis canyon had reached its present altitude (fig. 4a). The geomorphologic evolution of this area took place in three stages (fig. 8). 1) The Grands Causses acted as piedmont for the crystalline highlands of the Massif Central (fig. 8A). A latter karstic evolution (tropical climate) allowed the weathered residual sediments (facies 1) (fig. 8A). 2) Incision of the Vis karstic canyon implies that the Herault incision and terraces (facies 2) (fig, 8B) of the Airoles valley occurred during this stage. 3) The Arre valley head propagates westward by regressive erosion and finaly captured the Airoles river crystalline catchment (fig. 8C). Consequence for the Cevennes uplift and hydrographic network development Although the values of present vertical incision in the Vis canyon and in the Arre valley are similar, but they achieved at different time. In addition, the narrow and deep canyon of the Vis is due to vertical incision from the karstic surface of the Grands Causses, whereas the Arre wide valley results from (a younger) lateral slops retreat from a low Herault base-level. The Vis karstic canyon developed in a similar way to the major karstic canyons of both Mediterranean and Atlantic catchment (i.e. Tarn). This rules out a Messinian Mediterranean desiccation as incision driving mechanism and suggests tectonic uplift of the Cevennes and surrounding areas. The Tam being already incised by 13 My [Ambert, 1990], it implies a Miocene age for the incision. Conclusion The amplitude of the vertical incision cannot therefore be used in a simple way to interpret the uplift history of the basement. Consequently, geomorphologic analysis appears to be a prerequisite to distinguish the part played by each factor, and to select the site of uplift measurement

Diagenesis and porosity evolution of the Upper Silurian-lowermost Devonian West Point reef limestone, eastern Gaspe Belt, Quebec Appalachians, 2001, Bourque Pa, Savard Mm, Chi G, Dansereau P,
Diagenetic analysis based on cathodoluminescence petrography, cement stratigraphy, carbon and oxygen stable isotope geochemistry, and fluid inclusion microthermometry was used to reconstruct the porosity history and evaluate the reservoir potential of the Upper Silurian-Lower Devonian West Point limestone in the eastern part of the Gaspe Belt. The West Point limestone was investigated in two areas: 1) In the Chaleurs Bay Synclinorium, the limestone diagenesis of the lower and middle complexes of the Silurian West Point Formation was affected by repeated subaerial exposure related to late Ludlovian third-order eustatic low-stands, which coincided with the Salinic block tilting that produced the Salinic unconformity. The Anse McInnis Member (middle bank complex) underwent freshwater dissolution, and mixed marine and freshwater cementation during deposition. Concurrently, the underlying Anse a la Barbe and Gros Morbe members (lower mound and reef complex) experienced dissolution by fresh water percolating throughout the limestone succession. Despite this early development of karst porosity, subsequent meteoric-influenced cementation rapidly occluded all remaining pore space in the Gros Morbe, Anse a la Barbe, and Anse McInnis limestones. In contrast, the overlying Colline Daniel Member limestone (upper reef complex) does not show the influence of any freshwater diagenesis. Occlusion of its primary porosity occurred during progressive burial and was completed under a maximum burial depth of 1.2 kin. 2) In the Northern Outcrop Belt, the diagenesis of the Devonian pinnacle reefs of the West Point Formation followed a progressive burial trend. The primary pores of the reef limestone were not completely occluded before the reefs were buried at a significant depth (in some cases, to 6 km). Therefore, hydrocarbon migration in subsurface buildups before primary porosity occlusion might have created reservoirs. Moreover, the presence of gaseous hydrocarbons in Acadian-related veins attests to a hydrocarbon source in the area

Mineralogy and geochemistry of trace elements in bauxites: the Devonian Schugorsk deposit, Russia, 2001, Mordberg L. E. , Stanley C. J. , Germann K. ,
Processes of mineral alteration involving the mobilization and deposition of more than 30 chemical elements during bauxite formation and epigenesis have been studied on specimens from the Devonian Schugorsk bauxite deposit, Timan, Russia. Chemical analyses of the minerals were obtained by electron microprobe and element distribution in the minerals was studied by element mapping. Interpretation of these data also utilized high-resolution BSE and SE images. The main rock-forming minerals of the Vendian parent rock are calcite, dolomite, feldspar, aegirine, riebeckite, mica, chlorite and quartz; accessory minerals are pyrite, galena, apatite, ilmenite, monazite, xenotime, zircon, columbite, pyrochlore, chromite, bastnaesite and some others. Typically, the grain-size of the accessory minerals in both parent rock and bauxite is from 1 to 40 {micro}m. However, even within these rather small grains, the processes of crystal growth and alteration during weathering can be determined from the zonal distribution of the elements. The most widespread processes observed are: (1) Decomposition of Ti-bearing minerals such as ilmenite, aegirine and riebeckite with the formation of leucoxene', which is the main concentrator of Nb, Cr, V and W. Crystal growth can be traced from the zonal distribution of Nb (up to 16 wt.%). Vein-like leucoxene' is also observed in association with organics. (2) Weathering of columbite and pyrochlore: the source of Nb in leucoxene' is now strongly weathered columbite, while the alteration of pyrochlore is expressed in the growth of plumbopyrochlore rims around Ca-rich cores. (3) Dissolution of sulphide minerals and apatite and the formation of crandallite group minerals: crandallite' crystals of up to 40 {micro}m size show a very clear zonation. From the core to the rim of a crystal, the following sequence of elements is observed: Ca [->] Ba [->] Ce [->] Pb [->] Sr [->] Nd. Sulphur also shows a zoned but more complicated distribution, while the distribution of Fe is rather variable. A possible source of REE is bastnaesite from the parent rock. More than twelve crandallite type cells can be identified in a single crandallite' grain. (4) Alteration of stoichiometric zircon and xenotime with the formation of metamict solid solution of zircon and xenotime: altered zircon rims also bear large amounts of Sc (up to 3.5 wt.%), Fe, Ca and Al in the form of as yet unidentified inclusions of 1-2 {micro}m. Monazite seems to be the least altered mineral of the profile. In the parent rock, an unknown mineral of the composition (wt.%): ThO2 - 54.8; FeO - 14.6; Y2O5 -2.3; CaO - 2.0; REE - 1.8; SiO2 - 12.2; P2O5 - 2.8; total - 94.2 (average from ten analyses) was determined. In bauxite, another mineral was found, which has the composition (wt.%): ThO2 - 24.9; FeO - 20.5; Y2O5 - 6.7; CaO - 2.0; ZrO - 17.6; SiO2 - 8.8; P2O5 - 5.4; total - 89.3 (F was not analysed; average from nine analyses). Presumably, the second mineral is the result of weathering of the first one. Although the Th content is very high, the mineral is almost free of Pb. However, intergrowths of galena and pyrite are observed around the partially decomposed crystals of the mineral. Another generation of galena is enriched in chalcophile elements such as Cu, Cd, Bi etc., and is related to epigenetic alteration of the profile, as are secondary apatite and muscovite

Cave breakdown by vadose weathering, 2002, Osborne R. A. L.
Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coated, rather than having fresh broken faces, and blocks continue to disintegrate after separating from the bedrock. Not only gypsum, but also hydromagnesite and aragonite are responsible for crystal wedging. It is impossible to study or identify potential breakdown foci by surface surveys alone, in-cave observation and mapping are essential.

Genesis of the Dogankuzu and Mortas Bauxite Deposits, Taurides, Turkey: Separation of Al, Fe, and Mn and Implications for Passive Margin Metallogeny, 2002, Ozturk Huseyin, Hein James R. , Hanilci Nurullah,
The Taurides region of Turkey is host to a number of important bauxite, Al-rich laterite, and Mn deposits. The most important bauxite deposits, Do[g]ankuzu and Morta[s], are karst-related, unconformity-type deposits in Upper Cretaceous limestone. The bottom contact of the bauxite ore is undulatory, and bauxite fills depressions and sinkholes in the footwall limestone, whereas its top surface is concordant with the hanging-wall limestone. The thickness of the bauxite varies from 1 to 40 m and consists of bohmite, hematite, pyrite, marcasite, anatase, diaspore, gypsum, kaolinite, and smectite. The strata-bound, sulfide- and sulfate-bearing, low-grade lower part of the bauxite ore bed contains pyrite pseudomorphs after hematite and is deep red in outcrop owing to supergene oxidation. The lower part of the bauxite body contains local intercalations of calcareous conglomerate that formed in fault-controlled depressions and sinkholes. Bauxite ore is overlain by fine-grained Fe sulfide-bearing and calcareous claystone and argillaceous limestone, which are in turn overlain by massive, compact limestone of Santonian age. That 50-m-thick limestone is in turn overlain by well-bedded bioclastic limestone of Campanian or Maastrichtian age, rich with rudist fossils. Fracture fillings in the bauxite orebody are up to 1 m thick and consist of bluish-gray-green pyrite and marcasite (20%) with bohmite, diaspore, and anatase. These sulfide veins crosscut and offset the strata-bound sulfide zones. Sulfur for the sulfides was derived from the bacterial reduction of seawater sulfate, and Fe was derived from alteration of oxides in the bauxite. Iron sulfides do not occur within either the immediately underlying or overlying limestone. The platform limestone and shale that host the bauxite deposits formed at a passive margin of the Tethys Ocean. Extensive vegetation developed on land as the result of a humid climate, thereby creating thick and acidic soils and enhancing the transport of large amounts of organic matter to the ocean. Alteration of the organic matter provided CO2 that contributed to formation of a relatively 12C-rich marine footwall limestone. Relative sea-level fall resulted from strike-slip faulting associated with closure of the ocean and local uplift of the passive margin. That uplift resulted in karstification and bauxite formation in topographic lows, as represented by the Do[g]ankuzu and Morta[s] deposits. During stage 1 of bauxite formation, Al, Fe, Mn, and Ti were mobilized from deeply weathered aluminosilicate parent rock under acidic conditions and accumulated as hydroxides at the limestone surface owing to an increase in pH. During stage 2, Al, Fe, and Ti oxides and clays from the incipient bauxite (bauxitic soil) were transported as detrital phases and accumulated in the fault-controlled depressions and sinkholes. During stage 3, the bauxitic material was concentrated by repeated desilicification, which resulted in the transport of Si and Mn to the ocean through a well-developed karst drainage system. The transported Mn was deposited in offshore muds as Mn carbonates. The sulfides also formed in stage 3 during early diagenesis. Transgression into the foreland basin resulted from shortening of the ocean basin and nappe emplacement during the latest Cretaceous. During that time bioclastic limestone was deposited on the nappe ramp, which overlapped bauxite accumulation

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