Isotope geochemical (Sr,Nd)-peculiarities and sources of Mesozoic magmatic associations of the Umlekano-Ogodzhinskii belt (Amur Area)     

Sorokin  A. A.  Kovach  V. P.  Kotov  A. B.  Sorokin  A. P.  Ponomarchuk  V. A.  Zagornaya  N. Yu. 《Doklady Earth Sciences》2010,435(2):1650-1655

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First finds of native palladium,platinum, gold,and silver in brown coals of the Erkovets field (upper Amur region)     

V. I. Rozhdestvina  A. P. Sorokin 《Russian Journal of Pacific Geology》2010,4(6):483-494

Minerals of native elements (Pd, Pt, Au, Ag, and Au-Ag solid solutions) as well as Pb, Zn, Cu, Bi, Fe, Cr, Ni, W, Al, and their intermetallides, and a number of other ore minerals were discovered in brown coals of the Erkovets field. The structural reorganization of the noble metal grains and most of the other minerals found in the brown coals suggest their authigenic paragenesis. The input of noble metals in brown coals is possible in an ionic mode from the surface and underground waters as mineral particles transported by wind from goldfields.  相似文献   

Geochemical evidence for the ophiolitic nature of the gabbros,gabbroanorthosites, and ultramafic rocks of the Gerbikan fragment of the Baladek Massif of the southeastern framing of the North Asian craton     

A. A. Sorokin  I. V. Buchko  A. B. Kotov  S. D. Velikoslavinsky 《Russian Journal of Pacific Geology》2010,4(5):418-428

The Baladek Massif represents a tectonic block located at the boundary between the SE framing of the North Asian craton and the fold structures of the Galam terrane of the Mongol-Okhotsk fold belt. According to the existing concepts, the rocks of this massif are regarded as Precambrian complexes of the aforementioned craton. This paper reports the results of studying the fragment of the Baladek Massif in the Gerbikan River basin. New geochemical data obtained on the gabbros, gabbroanorthosites, and ultramafic rocks testify to their similarity with typical ophiolite complexes. An underlying complex of metamorphic ultrabasic rocks, a layered complex of pyroxenites and “cumulate” gabbros, gabbroanorthosites, and a complex of isotropic gabbros were distinguished within this fragment. It is highly possible that the basic volcanic rocks and jaspers of the Silurian-Lower Devonian sequences of the Galam segment of the Mongol-Okhotsk fold belt also belong to the inferred ophiolite complex.  相似文献   

First data on the noble metal geochemistry of the rocks from the gabbro-anorthosite massifs of the Kalar group     

I. V. Buchko  A. A. Sorokin 《Russian Journal of Pacific Geology》2010,4(6):461-469

This paper addresses the geochemical features of the noble metal disseminated sulfide and Timagnetite mineralization in the rocks of the Kalar group of autonomous gabbro-anorthosite massifs. The investigations suggest that this mineralization was formed in two stages. The first stage is related to the gabbroanorthosites proper and may be promising for low-sulfide PGE mineralization as well as PGE-bearing Ti-magnetite mineralization, while the second stage is linked to the ultrabasic intrusions associated with copper-nickel or chromite mineralization accompanying by PGE. The horizons of low-sulfide mineralization in the gabbro-anorthosites and copper-nickel mineralization in the dunite-pyroxenites are characterized by the Pd predominance over Pt, while the Cr-bearing and Ti-magnetite ores show the Pt predominance over Pd.  相似文献   

Areas and sources of Paleozoic metaterrigenous rocks of the Yankan terrane in the Mongolia-Okhotsk foldbelt: Evidence from the Sm-Nd isotope-geochemical studies     

A. A. Sorokin  A. A. Kolesnikov  A. B. Kotov  V. P. Kovach 《Doklady Earth Sciences》2014,454(2):204-207

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Geochemistry and tectonic depositional settings of Jurassic terrigenous sediments in the Upper Amur and Zeya-Dep troughs of the Eastern Central Asia fold belt     

Yu. N. Smirnova  A. A. Sorokin  L. I. Popeko 《Doklady Earth Sciences》2014,454(2):114-117

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Organic matter of oceanic sediments in the system of convective mass transfer in the lithosphere     

I. F. Savchenko  A. P. Sorokin  N. I. Belozerov  I. V. Girenko 《Doklady Earth Sciences》2014,458(1):1136-1138

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New 40Ar/39Ar age of granitic rocks and related gold mineralization at the Kirovskoye deposit (southeastern margin of the North Asian craton)     

A. A. Sorokin  A. V. Ponomarchuk  A. V. Travin  V. A. Ponomarchuk  K. D. Vakhtomin 《Doklady Earth Sciences》2014,458(2):1230-1235

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   

Sources of the Late Mesozoic magmatic associations in the northeastern part of the Amurian microcontinent     

A. A. Sorokin  A. B. Kotov  V. P. Kovach  V. A. Ponomarchuk  V. M. Savatenkov 《Petrology》2014,22(1):65-76

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   

Sources of the Jurassic terrigenous rocks of the Upper Amur and Zeya–Dep troughs of the eastern part of the Central Asian fold belt: Results of Sm–Nd isotopic–geochemical and U–Pb (LA-ICP-MS) geochronological studies     

Yu. N. Smirnova  A. A. Sorokin  A. B. Kotov  V. P. Kovach 《Doklady Earth Sciences》2015,465(2):1224-1228

The results of U–Pb geochronological studies of detrital zircons and Sm–Nd isotopic–geochemical studies of terrigenous rocks of the Upper Amur and Zeya–Dep troughs indicate that the beginning of orogenic processes, which led to the formation of the Mongol–Okhotsk fold belt, occurred in the Early Jurassic.  相似文献