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The first data on abnormally high δ13С values in hydrocarbonates (НСО 3-) dissolved in underground waters of coal deposits of Kuzbass (up to +30.9‰) are reported. It is shown that such an unusual isotope composition of waters results from the long, strictly directed interaction in the water–rock–gas–organic material system occurring under the conditions of hindered water exchange. Extensive fractionation of C isotopes is the result of the evolution of the water–rock–gas–coal system after penetration of infiltration waters into the coal deposits and their long interaction with all these components, rather than metamorphism of organic material upon its transformation into coal. With respect to such an approach, the isotope composition of dissolved C may indicate the duration of the evolution in the water–rock–gas–organic material system.  相似文献   
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Doklady Earth Sciences - Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the...  相似文献   
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The Kirovskoye gold deposit located in the southern part of the Selenga-Stanovoi superterrane at the southeastern margin of the Siberian craton is one of the largest ore deposits in the eastern regions of the Russian Far East. 40Ar/39Ar geochronological studies revealed that the age of the quartz-diorite-porphyrite and granodiorite-porphyry dikes is 128?126 Ma. This estimate agrees with the previous U-Pb age of 125 ± 2 Ma for the Dzhalinda granodiorites. The age of hydrothermal ore-forming processes was estimated at ~121?120 Ma. These results allow us to infer that a relationship between Kirovskoye gold mineralization was formed as a result of postmagmatic hydrothermal activity, which accompanied the emplacement of the Dzhalinda intrusion and coeval dikes.  相似文献   
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Based on generalization of available geochronological data, Late Mesozoic magmatic associations in the northeastern part of the Amurian microcontinent are divided into three groups: 142–125, 124–115, and <110 Ma. The age of these associations decreases with approaching the Pacific margin of Asia. In the same direction, they show a change in sources of their parental melts: continental crust (142–125 Ma) → continental crust + PREMA (DM) (124–115 Ma) → continental crust + PREMA (DM) + EMII (<110 Ma). Isotope-geochemical (Sr-Nd) study indicates that intrusive and volcanic rocks of the Late Mesozoic magmatic associations in the northeastern part of the Amurian microcontinent were originated in geodynamic settings that provided access of enriched mantle sources to magma formation. The most probable of these settings are as follows: (1) plate sliding accompanying by the formation of slab window beneath continental margin; (2) passage of the Asian margin over the East Asian mantle hot field in the Late Mesozoic; (3) asthenospheric upwelling due to delamination of the lower crust during closure of the Mongolian-Okhotsk ocean caused by collision between the Amurian microcontinent, Dzhugdzhur-Stanovoy, and Selenga-Stanovoy superterranes in the Central Asian fold belt.  相似文献   
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The Berezitovoe gold-polymetallic deposit is localized in the west of the Selenga–Stanovoi superterrane composed of a wide spectrum of Early and Late Precambrian igneous rocks and abundant Paleozoic and Mesozoic intrusive and volcanoplutonic associations. The 40Ar/39Ar ages determined for metasomatites bearing gold-polymetallic mineralization are as follows: garnet-quartz-muscovite-sericite-K-feldspathic metasomatites (129.7±3.2–127.3±4.4 Ma); muscovite-quartz-sericite metasomatites (132.0±2.9–131.3±2.3 Ma). According to the age and general scheme of evolution of the Early Cretaceous magmatism in the Selenga–Stanovoi superterrane, the metasomatites of the Berezitovoe deposit are nearly coeval to the intrusive rocks of the Amudzhikan complex (132–128 Ma). The revealed platinum potential of gold-polymetallic ores and metasomatites permits ranking the Berezitovoe deposit as a specific complex gold-polymetallic-platinum deposit, which considerably increases its commercial value.  相似文献   
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