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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

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That ground-water dam is a geological stratum serving as a subsurface dam [16].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for ore-deposits (Keyword) returned 24 results for the whole karstbase:
Showing 1 to 15 of 24
Karstic residual fluorite-baryte deposits at two localities in Derbyshire, 1983, Shaw R. P. ,
Various karst processes may rework primary mineralization producing secondary ore deposits in a variety of karstic cavities both on the surface and underground. Two surface localities, on Bonsall Moor, near Matlock, and near Castleton are filled with sediments containing locally derived fluorite and baryte clasts, in sufficient quantity to be worked as ore deposits. The associated clastic sediments are of Pleistocene fluvioglacial origin

Chemical hydrogeology in natural and contaminated environments, 1989, Back W, Baedecker Mj,
Chemical hydrogeology, including organic and inorganic aspects, has contributed to an increased understanding of groundwater flow systems, geologic processes, and stressed environments. Most of the basic principles of inorganic-chemical hydrogeology were first established by investigations of organic-free, regional-scale systems for which simplifying assumptions could be made. The problems of groundwater contamination are causing a shift of emphasis to microscale systems that are dominated by organic-chemical reactions and that are providing an impetus for the study of naturally occurring and manmade organic material. Along with the decrease in scale, physical and chemical heterogeneity become major controls.Current investigations and those selected from the literature demonstrate that heterogeneity increases in importance as the study site decreases from regional-scale to macroscale to microscale. Increased understanding of regional-scale flow systems is demonstrated by selection of investigations of carbonate and volcanic aquifers to show how application of present-day concepts and techniques can identify controlling chemical reactions and determine their rates; identify groundwater flow paths and determine flow velocity; and determine aquifer characteristics. The role of chemical hydrogeology in understanding geologic processes of macroscale systems is exemplified by selection of investigations in coastal aquifers. Phenomena associated with the mixing zone generated by encroaching sea water include an increase in heterogeneity of permeability, diagenesis of minerals, and formation of geomorphic features, such as caves, lagoons, and bays. Ore deposits of manganese and uranium, along with a simulation model of ore-forming fluids, demonstrate the influence of heterogeneity and of organic compounds on geochemical reactions associated with genesis of mineral deposits. In microscale environments, importance of heterogeneity and consequences of organic reactions in determining the distributions and concentrations cf. constituents are provided by several studies, including infiltration of sewage effluent and migration of creosote in coastal plain aquifers. These studies show that heterogeneity and the dominance of organically controlled reactions greatly increase the complexity of investigations

DIAGENESIS AND MINERALIZATION PROCESSES IN DEVONIAN CARBONATE ROCKS OF THE SIDING-GUDAN LEAD-ZINC MINERAL SUBDISTRICT, GUANGXI, SOUTHWEST CHINA, 1991, Schneider W. , Geng A. Q. , Liu X. Z. ,
The lead-zinc ore deposits of the Siding-Gudan mineral subdistrict Guangxi are part of the large Nanling district of South China, and hosted in Devonian carbonate rocks. The ore bodies occur significantly along main faults and fault zones, and concentrate up to 300 meters above the Cambrian/Devonian unconformity. Connected with hydrothermal karst, size and volume of the ore bodies increase in proximity to this unconformity. Moving from the unaffected host rocks to the center of the ore bodies, four zones can be discriminated by the mineral assemblage (pyrite, sphalerite, galena) as well as by the degree of ordering, Ca/Mg, and Fe/Mn ratios of different dolomites. Homogenization temperatures range from 80-100-degrees-C (Presqu'ile dolomite) to 230-260-degrees-C (massive sphalerite). The sulfides reveal delta-S-34 = -20 to parts per thousand, and fluid inclusions display a salinity of 5-12 wt % equivalent NaCl. The diagenetic and hydrothermal history is similar to that of classic Mississippi Valley Type (MVT) sulfide mineral deposits as, for example, Pine Point in Canada. Mineralization and remobilization of the sulfides took place during a wide time span from late Paleozoic through Mesozoic. Both processes are considered as an interaction of saline basinal brines ascended from the adjoining dewatering trough, and magmatic-hydrothermal fluids of several magmatic-tectonic events

LATE-STAGE DOLOMITIZATION OF THE LOWER ORDOVICIAN ELLENBURGER GROUP, WEST TEXAS, 1991, Kupecz J. A. , Land L. S. ,
Petrography of the Lower Ordovician Ellenburger Group, both in deeply-buried subsurface cores and in outcrops which have never been deeply buried, documents five generations of dolomite, three generations of microquartz chert, and one generation of megaquartz. Regional periods of karstification serve to subdivide the dolomite into 'early-stage', which predates pre-Middle Ordovician karstification, and 'late-stage', which postdates pre-Middle Ordovician karstification and predates pre-Permian karstification. Approximately 10% of the dolomite in the Ellenburger Group is 'late-stage'. The earliest generation of late-stage dolomite, Dolomite-L1, is interpreted as a precursor to regional Dolomite-L2. L1 has been replaced by L2 and has similar trace element, O, C, and Sr isotopic signatures, and similar cathodoluminescence and backscattered electron images. It is possible to differentiate L1 from L2 only where cross-cutting relationships with chert are observed. Replacement Dolomite-L2 is associated with the grainstone, subarkose, and mixed carbonate-siliciclastic facies, and with karst breccias. The distribution of L2 is related to porosity and permeability which focused the flow of reactive fluids within the Ellenburger. Fluid inclusion data from megaquartz, interpreted to be cogenetic with Dolomite-L2, yield a mean temperature of homogenization of 85 6-degrees-C. On the basis of temperature/delta-O-18-water plots, temperatures of dolomitization ranged from approximately 60 to 110-degrees-C. Given estimates of maximum burial of the Ellenburger Group, these temperatures cannot be due to burial alone and are interpreted to be the result of migration of hot fluids into the area. A contour map of delta-O-18 from replacement Dolomite-L2 suggests a regional trend consistent with derivation of fluids from the Ouachita Orogenic Belt. The timing and direction of fluid migration associated with the Ouachita Orogeny are consistent with the timing and distribution of late-stage dolomite. Post-dating Dolomite-L2 are two generations of dolomite cement (C1 and C2) that are most abundant in karst breccias and are also associated with fractures, subarkoses and grainstones. Sr-87/Sr-86 data from L2, C1, and C2 suggest rock-buffering relative to Sr within Dolomite-L2 (and a retention of a Lower Ordovician seawater signature), while cements C1 and C2 became increasingly radiogenic. It is hypothesized that reactive fluids were Pennsylvanian pore fluids derived from basinal siliciclastics. The precipitating fluid evolved relative to Sr-87/Sr-86 from an initial Pennsylvanian seawater signature to radiogenic values; this evolution is due to increasing temperature and a concomitant evolution in pore-water geochemistry in the dominantly siliciclastic Pennsylvanian section. A possible source of Mg for late-stage dolomite is interpreted to be from the dissolution of early-stage dolomite by reactive basinal fluids

LATE TO POSTHERCYNIAN HYDROTHERMAL ACTIVITY AND MINERALIZATION IN SOUTHWEST SARDINIA (ITALY), 1992, Boni M, Iannace A, Koppel V, Fruhgreen G, Hansmann W,
Several kinds of base metal deposits occur in the lower Paleozoic of southwest Sardinia (Iglesiente-Sulcis mineral district). This paper deals with those deposits which are generally referred to as Permo-Triassic, because they accompany and postdate the Hercynian orogeny and are related to magmatic activity. A large number of previously published geochemical data, integrated with additional new data (Sr, Pb, O, C, and S isotopes), are reviewed and discussed in the frame of the late to post-Hercynian geologic evolution of southwest Sardinia. According to geological and mineralogical characteristics, three types of deposits can be distinguished: (1) skarn ores related to late Hercynian leucogranitic intrusions, (2) high-temperature veins, and (3) low-temperature veins and karst filling. Pervasive epigenetic dolomitization phenomena are geochemically related to the low-temperature deposits. Sr and Pb isotopes of the first and second types (0.7097-0.7140 Sr-87/Sr-86; 17.97-18.29 Pb-206/Pb-204; 38.11-38.45 Pb-208/Pb-204) are distinctly more radiogenic than those of the third type (0.7094-0.7115 Sr-87/Sr-86; 17.86-18.05 Pb-206/Pb-204; 37.95-38.19 Pb-208/Pb-204) which, in turn, are closer to Paleozoic ores and carbonates. Fluid inclusion data indicate that the fluids responsible for mineralization of the first and second types of deposits were hot and dilute (T(h)= 370-degrees-140-degrees-C; <5 wt % NaCl equiv). In contrast, relatively colder and very saline fluids (T(h)= 140-degrees-70-degrees-C; >20 wt % NaCl equiv) were responsible for the third type of mineralization, as well for epigenetic dolomitization of the Cambrian host rocks. O isotopes measured in minerals from the first two types (deltaO-18SMOW = 12.8-18.9 parts per thousand) are O-18 depleted with respect to the third type (deltaO-18SMOW = 15.9-22.1 parts per thousand). These data, coupled with fluid inclusion formation temperatures, indicate that the fluids responsible for the first two types of mineralization were O-18 enriched with respect to those of the third type and related hydrothermal phenomena. The deltaS-34CDT in sulfides of the first two types vary between 3.7 and 10.73 per mil, whereas the values of the third type range from 12.0 to 17.9 per mil. Late to post-Hercynian mineralization is thus explained as the result of three distinct, though partly superimposed, hydrothermal systems. System 1 developed closer to the late Hercynian leucogranitic intrusions and led to the formation of the first and subsequently the second type of mineralization. The relatively hot and diluted fluids had a heated meteoric, or even partly magmatic, origin. Metals were leached from an external, radiogenic source, represented either by Hercynian leucogranites or by Paleozoic metasediments. Sulfur had a partly magmatic signature. System 2 was characterized by very saline, colder fluids which promoted dolomitization, silicification, and vein and karst mineralization. These fluids share the typical characteristics of formation waters, even though their origins remain highly speculative. The hydrothermal system was mainly rock dominated, with only a minor participation of the external radiogenic source of metals. Sulfur was derived by recirculation of pre-Hercynian strata-bound ores. System 3 records the invasion of fresh and cold meteoric waters which precipitated only minor ore and calcite gangue. It may represent the further evolution of system 2, possibly spanning a time well after the Permo-Triassic. The timing of all these phenomena is still questionable, due to the poor geologic record of the Permo-Triassic in southwest Sardinia. Nevertheless, the hypothesized scenario bears many similarities with hydrothermal processes documented throughout the Hercynian in Europe and spanning the same time interval. A comparison with the latter mineralization and hydrothermal activities leads to the hypothesis that the first two types of mineralization are linked to late Hercynian magmatic activity, whereas the third type may be related to either strike-slip or tensional tectonics which, throughout Europe mark the transition from the Hercynian orogeny to the Alpine cycle

CHEMICAL-REACTION PATH MODELING OF ORE DEPOSITION IN MISSISSIPPI VALLEY-TYPE PB-ZN DEPOSITS OF THE OZARK REGION UNITED-STATES MIDCONTINENT, 1994, Plumlee G. S. , Leach D. L. , Hofstra A. H. , Landis G. P. , Rowan E. L. , Viets J. G. ,
The Ozark region of the U.S. midcontinent is host to a number of Mississippi Valley-type districts, including the world-class Viburnum Trend, Old Lead Belt, and Tri-State districts and the smaller Southeast Missouri barite, Northern Arkansas, and Central Missouri districts. There is increasing evidence that the Ozark Mississippi Valley-type districts formed locally within a large, interconnected hydrothermal system that also produced broad fringing areas of trace mineralization, extensive subtle hydrothermal alteration, broad thermal anomalies, and regional deposition of hydrothermal dolomite cement. The fluid drive was provided by gravity flow accompanying uplift of foreland thrust belts during the Late Pennsylvanian to Early Permian Ouachita orogeny. In this study, we use chemical speciation and reaction path calculations, based on quantitative chemical analyses of fluid inclusions, to constrain likely hydrothermal brine compositions and to determine which precipitation mechanisms are consistent with the hydrothermal mineral assemblages observed regionally and locally within each Mississippi Valley-type district in the Ozark region. Deposition of the regional hydrothermal dolomite cement with trace sulfides likely occurred in response to near-isothermal effervescence of CO2 from basinal brines as they migrated to shallower crustal levels and lower confining pressures. In contrast, our calculations indicate that no one depositional process can reproduce the mineral assemblages and proportions of minerals observed in each Ozark ore district; rather, individual districts require specific depositional mechanisms that reflect the local host-rock composition, structural setting, and hydrology. Both the Northern Arkansas and Tri-State districts are localized by normal faults that likely allowed brines to rise from deeper Cambrian-Ordovician dolostone aquifers into shallower carbonate sequences dominated by limestones. In the Northern Arkansas district, jasperoid preferentially replaced limestones in the mixed dolostone-limestone sedimentary packages. Modeling results indicate that the ore and alteration assemblages in the Tri-State and Northern Arkansas districts resulted from the flow of initially dolomite-saturated brines into cooler limestones. Adjacent to fluid conduits where water/rock ratios were the highest, the limestone was replaced by dolomite. As the fluids moved outward into cooler limestone, jasperoid and sulfide replaced limestone. Isothermal boiling of the ore fluids may have produced open-space filling of hydrothermal dolomite with minor sulfides in breccia and fault zones. Local mixing of the regional brine with locally derived sulfur undoubtedly played a role in the development of sulfide-rich ore runs. Sulfide ores of the Central Missouri district are largely open-space filling of sphalerite plus minor galena in dolostone karst features localized along a broad anticline. Hydrothermal solution collapse during ore deposition was a minor process, indicating dolomite was slightly undersaturated during ore deposition. No silicification and only minor hydrothermal dolomite is present in the ore deposits. The reaction path that best explains the features of the Central Missouri sulfide deposits is the near-isothermal mixing of two dolomite-saturated fluids with different H2S and metal contents. Paleokarst features may have allowed the regional brine to rise stratigraphically and mix with locally derived, H2S-rich fluids

LAND SUBSIDENCE, SINKHOLE COLLAPSE SAND EARTH FISSURE OCCURRENCE AND CONTROL IN CHINA, 1994, Deng As, Ju Jh,
There are many varieties of geological hazard in China which are widely dispersed. Land subsidence is one such hazard and occurs mainly in the coastal cities of east China. Sinkhole collapses are mainly found near those cities of east and middle China that have karst water and karst water-impregnated ore deposits. Earth fissures also occur in east and middle China. All these geological hazards have a great influence upon the construction of engineering works. Though the causes of the hazards may be different, a major contributor is human economic activity. Therefore, a major countermeasure is to control human economic development

THE KASKASKIA PALEOKARST OF THE NORTHERN ROCKY-MOUNTAINS AND BLACK-HILLS, NORTHWESTERN USA, 1995, Palmer A. N. , Palmer M. V. ,
The Kaskaskia paleokarst, part of the Mississippian-Pennsylvanian unconformity in North America, is typified by sinkholes, fissures, and dissolution caves at and near the top of the Kaskaskia Sequence (Madison Limestone and equivalents) and is covered by basal Absaroka siliciclastics (Chesterian to Morrowan). In the Rocky Mountains and Black Hills of the northwestern U. S. A. it postdates earlier features produced by sulfate-carbonate interactions, including breccias, dissolution voids, bedrock alteration, and mineralization. Both the paleokarst and earlier features have been intersected by post-Laramide caves. Ore deposits, aquifers, and petroleum reservoirs in the region are also concentrated along both the paleokarst horizons and earlier sulfate-related features. Each phase of karst modified and preferentially followed the zones of porosity and structural weakness left by earlier phases, producing an interrelated complex of now-relict features. All should be considered together to explain the present aspect of the paleokarst

Geology and ore genesis of the manganese ore deposits of the Postmasburg manganese-field, South Africa, 1995, Plehweleisen E. , Klemm D. D. ,

GEOLOGY AND ORE GENESIS OF THE MANGANESE ORE-DEPOSITS OF THE POSTMASBURG MANGANESE-FIELD, SOUTH-AFRICA, 1995, Vonplehweleisen E. , Klemm D. D. ,
The Postmasburg Mn/Fe-ores occur exclusively in dolomitic Precambrian sinkhole structures with siliceous breccias and shales as hostrocks. The main manganese minerals are braunite and bixbyite, apart from secondary alteration products of the psilomelane-manganomelane family. Various generations of ore minerals could be identified. The ore mineralization is subdivided into three different genetic types. They are classified either as pure karst deposits or as combined formations of karst origin and shallow marine sedimentation due to the transgression of the Banded Iron Formation (BIF) sea. Post-sedimentary metamorphism is identified as very low grade. The development of the different ore types is illustrated schematically

Occurrence and significance of stalactites within the epithermal deposits at Creede, Colorado, 1996, Campbell Wr, Barton Pb,
In addition to the common and abundant features in karst terranes, stalactites involving a wide variety of minerals have also been found in other settings, including epigenetic mineral deposits, bur these are almost always associated with supergene stages. Here we describe a different mode of occurrence from the Creede epithermal ore deposits, in Colorado, wherein stalactites of silica, sphalerite, galena, or pyrite formed in a vapor-dominated setting, below the paleo-water table, and except possibly for pyrite, as part of the hypogene mineralization. Axial cavities may, or may not, be present. No stalagmites have been recognized. The stalactites are small, from a few millimeters to a few centimeters long and a few millimeters in outer diameter. They represent only a small fraction of one percent of the total mineralization, and are covered by later crystals. Their growth orientation usually is unobservable; however, the parallel arrangement of all stalactites in a given specimen, consistency with indicators of gravitational settling, and the common presence of axial structures make the stalactitic interpretation almost unavoidable. In contrast with common carbonate stalactites, the growth mechanism for th sulfide and silica stalactites requires extensive evaporation. Stalactitic forms have also been reported from other deposits, mostly epithermal or Mississippi Valley-type occurrences, but we caution that stalactite-like features can form by alternative processes

Geology, geochemistry, and origin of the continental karst-hosted supergene manganese deposits in the western Rhodope massif, Macedonia, northern Greece, 1997, Nimfopoulos M. K. , Pattrick R. A. D. , Michailidis K. M. , Polya D. A. , Esson J. ,
Economic Mn-oxide ore deposits of commercial grade occur in the Rhodope massif near Kato Nevrokopi in the Drama region, Northern Greece. The Mn-oxide mineralization has developed by weathering of continental hypogene rhodochrosite-sulphide veins. The vein mineralization is confined by tectonic shear zones between marble and metapelites, extending laterally into the marble as tabular, pod or lenticular oreshoots (up to 50 m x 20 m x 5-10 m). Supergene oxidation of the hypogene mineralization led to the formation of in-situ residual Mn-oxide ore deposits, and secondary infills of Mn-oxide ore in embryonic and well developed karst cavities. Whole rock geochemical profiles across mineralized zones confirm the role of thrusts and faults as solution passageways and stress the importance of these structures in the development of hydrothermal and supergene mineralization at Kato Nevrokopi. Three zones an recognized in the insitu supergene veins: (A) a stable zone of oxidation, where immobile elements form (or substitute in) stable oxide mineral phases, and mobile elements are leached; (B) a transitional (active) zone in which element behavior is strongly influenced by seasonal fluctuations of the groundwater table and variations in pH-Eh conditions; and (C) a zone of permanent flooding, where variations in pH-Eh conditions are minimal. Zone (B) is considered as the source zone for the karst cavity mineralization. During weathering, meteoric waters, which were CO2-rich (P-CO2 similar to 10(-3.8) to 10(-1.4)) and oxygenated (fO(2) -10(-17) for malachite), percolated downward within the veins, causing breakdown and dissolution of sulfides and marble, and oxidation of rhodochrosite to Mn-oxides. Karat cavity formation was favored by the high permeability along thrust zones. Dissolved Mn2 was transported into karst cavities in reduced meteoric waters at the beginning of weathering (pH similar to 4-5), and as Mn(HCO3)(2) in slightly alkaline groundwaters during advanced weathering (pH similar to 6-8). Mn4? precipitation took place by fO(2) increase in ground waters, or pH increase by continuous hydrolysis and carbonate dissolution. In the well developed karst setting, some mobility of elements occurred during and after karst ore formation in the order Na>K>Mg>Sr>Mn>As>Zn>Ba>Al>Fe>Cu>Cd>Pb. (C) 1998 Canadian Institute of Mining, Metallurgy and Petrolem. Published by Elsevier Science Ltd. All rights reserved

Organic matter in the Upper Silesian (Mississippi Valley-type) Zn-Pb deposits, Poland, 1999, Sassgustkiewicz M. , Kwiecinska B. ,
Organic matter contained in large amounts in the Upper Silesian Zn-Pb ore deposits has been identified as dopplerite-calcium humate. This humic, amorphous substance was precipitated from humic acids by calcium ion loading. The precipitation of dopplerite was contemporaneous with sulfide deposition at the time of initial and mature karst processes. The hydrothermal karst dissolution supplied calcium ions but the source of humic acids is still conjectural. The geochemical data indicate that the most probable source for the organic matter deposited in the Zn-Pb ores are overlying Triassic Keuper shales containing dispersed humic organic substance

Sinkholes in karst mining areas in China and some methods of prevention, 1999, Li G. Y. , Zhou W. F. ,
Mining of coal, lead and zinc, gold, and iron ore deposits in karst areas has been closely associated with sinkholes in China. Surface collapse causes an increase in mine water drainage and the possibility of major water inflow from karst aquifers, which threatens the environment in mining areas and endangers the mine safety. A combination of factors including soil weight, buoyancy, suffusion process and vacuum suction can contribute to the sinkhole formation. The key measures to prevent sinkholes in mining areas are to control the amount of mine drainage, reduce water level fluctuation, seal-off karst conduits and subsurface cavities in the overlying soil, prevent water inflow, and/or to increase gas pressure in the karst conduits. (C) 1999 Elsevier Science B.V. All rights reserved

The reconstruction of fossil planation surface in China, 2002, Feng Jl, Cui Zj,
On the basis of results of relative subjects, the fossil planation surface has been discussed by the authors from the point of geomorphologic view. The discussion contents included the characteristic information, research methods, paleotopography (gradient and altitude) and other problems about fossil planation surface. The recognition and reconstruction of fossil planation surface mainly rely on the following characteristic information: ( i) the character of erosion unconformity surface; (ii) the paleo-weathering crust and residual deposits; (iii) the paleo-karst and filled deposit in the paleo-karst under the unconformity surface, and (iv) the character and environment of sediment above the unconformity surface. According to the above-mentioned characteristic information, the authors recognized and reconstructed two stages of fossil planation surface on Paleo-land of North China and Yangtze Paleo-land. These two fossil planation surfaces formed from Middle Ordovician to Lower Carboniferous and from Lower Permian to Upper Permian respectively. The paleo-gradient of fossil planation surface changed within 0.31parts per thousand-1.32parts per thousand, mostly less than 1.0parts per thousand. According to the developing depth of paleo-karst, the authors considered that in Suqiao buried-hill region of Paleo-land of North China, the paleo-altitude is 300 m or so above paleo-sea-level. The authors hope that the research is in favor of discussion about rising scale and process of the Tibetan Plateau. Besides, the research of fossil planation surface can provide a theoretical base for relative research, such as the reconstruction of paleoenvironment, the evolution and drift of paleo-continent, the formation and distribution of weathering ore deposits, the reservior and prospection of oil and gas, etc

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