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A.D. Nozhkin A.A. Postnikov K.E. Nagovitsin A.V. Travin A.M. Stanevich D.S. Yudin 《Russian Geology and Geophysics》2007,48(12):1015-1025
Trachybasalt-alkali trachyte volcanism in the Yenisei Ridge was found out to be synchronous with deposition of coarse tilloids and flysch of the Chivida Formation of the Neoproterozoic Chingasan Group. New 703±4 Ma 40Ar/39Ar biotite and titan-augite ages of subalkaline basalts in the Chivida Formation indicated that they erupted in the Late Neoproterozoic. According to microfossil evidence, the Chingasan sediments correlate with Late Neoproterozoic strata in the type sections of the southern Siberian craton. The Chingasan deposition apparently lasted no longer than 30 Myr judging by the isotope ages obtained for the underlying Upper Vorogovka Group and subalkaline basalts in the Chivida Formation. The fault-parallel position of grabens and coarse grain sizes and variable thicknesses of their lithological complexes, as well as syndepositional trachybasalt-alkali trachyte volcanism provided evidence that the volcanosedimentary rocks of the Chingasan Group formed in an environment of active rifting. 相似文献
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Postnikov A. V. Postnikova O. V. Iz”yurova E. S. Poshibaev V. V. Kuznetsov A. S. Iz”yuraov A. D. Kozionov A. E. 《Lithology and Mineral Resources》2019,54(1):27-37
Lithology and Mineral Resources - Main regularities in the manifestation of epigenetic processes in Lower Vendian terrigenous rocks of the Nepa–Botuoba anteclise are established. Evolution of... 相似文献
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O. V. Postnikova A. V. Postnikov E. S. Konoval’tseva V. G. Toporkov S. I. Savchenko 《Lithology and Mineral Resources》2011,46(5):447-456
Basic regularities of secondary processes in reservoir rocks of the Yarakta Horizon are described with rocks in the Yarakta
field as example. To achieve the formulated goal, we elucidated rock types in the studied section, its structure and distribution
of reservoir rocks, as well as types of secondary alterations and their influence on filtration-capacity properties. The studies
revealed that reservoir rocks of the Yarakta Horizon were formed on an alluvial-deltaic plain on the southeastern slope of
the Nepa-Botuoba anteclise. The pore space of reservoir rocks is determined by conditions of their formation and peculiarities
of secondary alterations. Maximal filtration-capacity values are characteristic of gritstones, as well as coarse-grained and
inequigranular sandstones developed in the lower and middle parts of the Yarakta Horizon. The intergranular space of reservoir
rocks in the lower part of the reservoir is substantially “healed” by secondary processes (regeneration, dolomitization, sulfatization,
and salinization), probably, due to the gravitational seepage of stratal fluids, mineralization of which increased with time. 相似文献
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A.E. Kontorovich A.I. Varlamov D.V. Grazhdankin G.A. Karlova A.G. Klets V.A. Kontorovich S.V. Saraev A.A. Terleev S.Yu. Belyaev I.V. Varaksina A.S. Efimov B.B. Kochnev K.E. Nagovitsin A.A. Postnikov Yu.F. Filippov 《Russian Geology and Geophysics》2008,49(12):932-939
The Borehole Vostok 3 drilled in the east of the West Siberian Plate (Tomsk Region) revealed a Vendian section in the depth range 5002–3870 m, which was subdivided into the Poiga, Kotodzha, and Raiga Formations based on geological, geophysical, and paleontological data. In the Kotodzha and Raiga Formations, typical Upper Vendian fossils of Cloudina hartmanae and Namacalathus sp. were found along with diverse Platysolenites, which are commonly considered to be of zonal significance in Lower Cambrian strata. Hence, the stratigraphic interval with abundant diverse Platysolenites has a wider stratigraphic range than it was believed earlier and seems to cover the Upper Vendian and Lower Cambrian deposits. The Borehole Vostok 3 is the first Siberian occurrence of the fossils Namacalathus, the world's fourth occurrence of the Cloudina-Namacalathus association, and the first site where coexisting Platysolenites and typical Vendian organisms have been found. Therefore, the borehole provides one of the most informative (in paleontological context) Upper Vendian sections. 相似文献
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A. V. Kargin A. A. Nosova A. V. Postnikov A. V. Chugaev O. V. Postnikova L. P. Popova V. V. Poshibaev L. V. Sazonova A. Ya. Dokuchaev M. D. Smirnova 《Geology of Ore Deposits》2016,58(5):383-403
The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb–Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali–ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali–ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite. 相似文献
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Kuranakh complex diabases in the western part of the Aldan-Stanovoi Shield: Age and tectonic setting
N. V. Popov A. B. Kotov E. B. Salnikova A. A. Postnikov V. F. Timofeev V. I. Berezkin A. M. Larin A. M. Fedoseenko S. Z. Yakovleva 《Doklady Earth Sciences》2012,442(1):45-48
The age of Kuranakh Complex diabases in the western part of the Aldan-Stanovoi Shield determined by the zircon U-Pb method
is virtually identical to that of basic rocks in the Chinei stratified pluton and granites in the Kodar Complex. Thus, it
is possible to suggest that they form a unified bimodal magmatic association and belong to the South Siberian postcollision
magmatic belt, which extends along the southwestern framing of the Siberian Craton for more than 2500 km from the Yenisei
mountain range to the Aldan-Stanovoi Shield. The occurrence of the diabase dike swarms in magmatic associations of this belt
testifies to formation under lithospheric extension conditions. 相似文献
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E. V. Bibikova S. V. Bogdanova A. V. Postnikov L. P. Popova T. I. Kirnozova M. M. Fugzan V. V. Glushchenko 《Stratigraphy and Geological Correlation》2009,17(6):561-573
The geochronologic (U-Pb isotopic system of zircons) and isotopic-geochemical (Sm-Nd isotopic system of the bulk rock) studies
were performed along the profile extending from the eastern Sarmatia (in the west) to the Middle Volga megablock of Volgo-Uralia
(in the east), i.e., across the entire junction zone for dating the integration of Sarmatia and Volgo-Uralia, representing
two segments of the East European Craton. It is established that the examined rocks are characterized by the Paleoproterozoic
Nd isotopic model age, which varies from 2.1 and 2.4 Ga, except for some samples indicating a similar age of the crust through
the entire Sarmatia-Volgo-Uralia junction zone. The highly metamorphosed complexes of the granulite and amphibolite facies
constituting the southwestern margin of Volgo-Uralia are Paleoproterozoic, not Archean, in age, contrary to previous views.
Two Early Paleoproterozoic lithotectonic complexes are defined in Volgo-Uralia: South Volga metasedimentary and Tersa metasedimentary-volcanogenic.
The obtained data confirm the asynchronous integration of individual segments into the East European Craton: the integration
of Sarmatia and Volgo-Uralia approximately 2100–2000 Ma ago was followed by the conjunction of this newly-formed continent
with Fennoscandia ca. 1800 Ma ago. 相似文献
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