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It has been demonstrated that the application of the moving window method for statistical processing of large volumes of geochemical information by the paired correlation method makes it possible to follow with great detail and obviousness the variability of correlations between chemical elements across a lithological section and hence to analyze sedimentation conditions in a sedimentary sequence and postsedimentary transformations of sedimentary rocks. 相似文献
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The ore-forming role of black shales is discussed. Correlation of their distribution with high phosphorus and manganese concentrations
is shown. Associations of black shales, phosphorites, and manganese ores are described. A mechanism is proposed for explaining
their co-occurrence in natural environments. It is emphasized that back shales serve as not only ore-forming sequences, but
also ore-generating formations for phosphorus and manganese deposits, as well as ore-concentrating rocks for chalcophile elements. 相似文献
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Economic significance of the sedimentary iron ore deposits is shown. The most important types of these deposits are characterized and their genesis is considered. Special attention is given to the formation of goethite-chlorite-siderite ooliths, which represent the main component of marine iron ore deposits. Geochemical and mineralogical features of different types of iron ores are examined. 相似文献
4.
Yu. O. Gavrilov E. V. Shchepetova E. A. Shcherbinina O. V. Golovanova R. I. Nedumov B. G. Pokrovsky 《Lithology and Mineral Resources》2017,52(6):447-466
Upper Eocene and Lower Oligocene rocks in the northeastern Caucasus were examined in the most representative Chirkei section (Sulak River basin). Sharp lithogeochemical distinctions between them were revealed. The results of the study of nannoplankton demonstrated that the Eocene/Oligocene interface occurs slightly below the boundary between the Belaya Glina and Khadum formations. The studied section revealed a series of nannoplankton bioevents facilitating its stratigraphic subdivision. It has been established that organic matter (OM) in rocks of the Khadum Formation is characterized by a relatively high degree of maturity. Probably, the material of mainly marine genesis contains a terrigenous OM admixture. Positive oxygen isotope anomaly in the upper part of the Belaya Glina Formation reflects global climate changes (cooling) near the Eocene/Oligocene interface. Limitation of the anomaly by the upper boundary of the Belaya Glina Formation is likely related to changes in water salinity variations in the Early Oligocene basin and intense early diagenetic processes in rocks therein. Lithological, geochemical, and paleoecological data suggest that the Khadum paleobasin was depleted in oxygen. Such environment was unstable with periodic intensification or attenuation. Paleoecology in the Belaya Glina basin was typical of normally aerated basins. 相似文献
5.
The article is dedicated to the geological structure and spatial position of the Cimmerian Kerch-Taman iron ore basin. Based on paleogeographic and recent geochemical data, it is shown that iron accumulated in the Cimmerian brackish lake originated mostly from weathered old rocks of the Ukrainian shield. The metal in question was delivered to the basin by its multistage migration and concentration owing to processes, which involved the eluvial zone of weathering crusts, krasnozem soils, rivers, bogs, and limans surrounding the lake. The formation mechanism of iron ore deposits is considered with the assessment of prospects for the discovery of new Cimmerian deposits in the spacious West Kuban depression and Crimea region and offshore areas of the Azov and Black seas. 相似文献
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The article is dedicated to regularities in the distribution of sedimentary phosphorite and manganese deposits in the Lower Paleozoic and Proterozoic formations. Special attention is paid to co-occurrence of phosphate and manganese ores formed during the Vendian-Cambrian shale formation epoch. It is shown that shale formation in certain epochs of the Precambrian and Phanerozoic was determined by the excess influx of carbon and biogenic elements to seas and marginal parts of the oceans and by enhanced productivity of planktonic organisms in corresponding geological periods. 相似文献
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R. I. Nedumov 《Lithology and Mineral Resources》2006,41(1):15-26
Conditions and scales of the accumulation of dissolved manganese in waters of marine basins with hydrosulfuric contamination
are considered. It is shown that the Kalamit ferromanganese nodule field, most probably, originated due to the delivery of
manganese from the hydrosulfuric zone of the Black Sea. Precisely this source converts the normal diagenetic process of material
redistribution into the ore process. It is demonstrated that the formation of ferromanganese nodules in the Black Sea represents
an embryonic manganese ore process. Its full-scale development seems to have taken place in the Early Oligocene Maikop basin
owing to the spatiotemporal coincidence of a series of favorable conditions. 相似文献
10.
Mineralogical-geochemical features of different facies types of sedimentary iron ore deposits are described. Particular attention is paid to deposits associated with the weathering crusts of ultramafic igneous rocks and to marine oolitic iron ores. The multistage formation of their geochemical properties is proved available geochemical models are considered. 相似文献