Stages of Tectono-Magmatic Activity in the Border Zone of the Siberian Platform and the Tannuola–Khamsara Segment of the CAFB (According to the Results of U–Pb Isotope Studies)     

Shkolnik  S. I.  Letnikova  E. F.  Reznitskii  L. Z.  Ivanov  A. V.  Proshenkin  A. I. 《Doklady Earth Sciences》2021,498(2):451-455

Doklady Earth Sciences - Based on the dating of metamorphic and igneous rocks of the northeastern part of the Khamsara terrane, the main stages of tectono-magmatic activity at the border of two...  相似文献   

Source Provenance and Paleogeographic Conditions during Deposition of Jurassic Continental Sediments in the Southern Part of the Siberian Platform (Implication of Sm–Nd and U–Pb Data)     

E. I. Demonterova  A. V. Ivanov  E. A. Mikheeva  A. V. Arzhannikova  A. O. Frolov  S. G. Arzhannikov  N. V. Bryanskiy  L. A. Pavlova  L. Z. Reznitskii  O. V. Zarubina 《Doklady Earth Sciences》2018,480(2):720-724

The first Sm–Nd isotopic data and U–Pb (LA–ICP–MS) detrital zircon ages from sandstones of the Prisayan and Kuda Formations (the Irkutsk Basin, southern part of the Siberian Platform) have been obtained. They demonstrate that during accumulation of the sediments in the Irkutsk Basin, the contribution of local erosion sources decreased over time, while input from the Paleo–Transbaikalia sources increased. The change in provenance areas was triggered by tectonic rebuilding in Paleo–Transbaikalia caused by the closure of the Mongol–Okhotsk Ocean.  相似文献   

Age constraints of high-temperature metamorphic events in crystalline complexes of the Irkut block,the Sharyzhalgai ledge of the Siberian platform basement: Results of the U-Pb single zircon dating     

E. B. Sal’nikova  A. B. Kotov  V. I. Levitskii  L. Z. Reznitskii  A. I. Mel’nikov  I. K. Kozakov  V. P. Kovach  I. G. Barash  S. Z. Yakovleva 《Stratigraphy and Geological Correlation》2007,15(4):343-358

Geochronological data obtained in this work and previously known results of U-Pb geochronology suggest that principal metamorphic events, which took place in eastern part of the Irkut block (the Sharyzhalgai marginal ledge of the Siberian platform basement), correspond in age to (1) about 2.8 Ga, (2) 2649 ± 6 to 2562 ± 20 Ma, and (3) 1865 ± 4 to 1855 ± 5 Ma. Structural and metamorphic reworking of the earliest event originated under conditions of the granulite facies, whereas conditions of granulite and amphibolite facies were characteristic of the second and third events. Metasomatites after carbonate rocks originated in eastern part of the Sharyzhalgai ledge during the Early Proterozoic metamorphic event that lasted approximately 20 m.y. Being combined with age data, which are known at present for the reference syn-and post-collision granitoids in the Siberian platform basement and flanking foldbelts, new geochronological results show that accretion of basement blocks to the Siberian craton progressed from the east to the west between 1900 and 1840 Ma. To a first approximation, this geochronological interval characterizes time span of the Paleoproterozoic ocean closure and ultimate time, when the craton and supercontinent Columbia became amalgamated.  相似文献   

Main stages of tectonomagmatic activity of the Tuva–Mongolian microcontinent in the Precambrian: data on the U–Pb age of zircons     

E. F. Letnikova  S. I. Shkolnik  F. A. Letnikov  E. A. Karakovskii  Yu. A. Kostitsyn  I. A. Vishnevskaya  L. Z. Reznitskii  A. V. Ivanov  A. I. Prochenkin 《Doklady Earth Sciences》2017,474(2):668-673

The U–Pb age of zircons from Ediacaran sandstones of the cover of the Tuva–Mongolian microcontinent and the rocks of its Early Precambrian basement (Gargan block) was analyzed by the LA–ICP–MS method. The major stages of tectonomagmatic activity of this block include the Neoarchean, Paleoproterozoic (no younger than 2 Ga), and Neoproterozoic. Comparison of the age of zircons from Ediacaran terrigenous rocks of the Tuva–Mongolian microcontinent and sandstones of the reference sections of the Ediacaran shelf of the Siberian platform undeniably indicates their independent accumulation.  相似文献   

A Vendian manganese-bearing basin of the Ikat terrane: Formation settings and provenance areas     

S. I. Shkolnik  E. F. Letnikova  A. V. Maslov  M. D. Buyantuev  L. Z. Reznitskii  I. G. Barash 《Doklady Earth Sciences》2017,475(1):739-742

The results of geochemical, mineralogical, and isotope (U–Pb and Sm–Nd) studies of metasedimentary manganese-bearing rocks from the Itantsa Formation of the Ikat terrane are presented. It is found that the carbonate-effusive-shale complex of the Itantsa Fm. formed under the continental margin environment, with volcanic activity accompanying sedimentation, in the interval of 650–540 Ma ago.  相似文献   

Atomic arrangements around the O3 site in Al- and Cr-rich oxy-tourmalines: a combined EMP,SREF, FTIR and Raman study     

Ferdinando Bosi  Henrik Skogby  Peter Lazor  Leonid Reznitskii 《Physics and Chemistry of Minerals》2015,42(6):441-453

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A fragment of back-arc paleospreading in the Tunka terrane     

S. I. Shkol’nik  V. G. Belichenko  L. Z. Reznitskii  I. G. Barash 《Doklady Earth Sciences》2011,436(1):61-65

High magnesium metavolcanites, which are found for the first time in the Tunka terrane (the Baikal-Khubsogul region), are described. By the content of MgO (12–16%), SiO₂ (up to 52%), and alkali oxides, they are classified as metamorphosed picrites. There are two groups of them, divided by the TiO₂ content and by the TiO₂/Al₂O₃ ratio. When making a distinction between geochemical peculiarities of two groups, their rare-element composition is intermediate between picrites and boninites. The comparison between metavulcanites and their nonmetamorphosed analogues is made, some aspects of their genesis are considered, and the conclusion is made that these metavulcanites mark paleospreading of the back-arc basin.  相似文献   

Formation history of the Tuva-Mongolian Massif (Western Hubsugul region, North Mongolia) based on U-Pb dating of detrital zircons from sandstone of the Darkhat group by the LA-ICP-MS method     

E. I. Demonterova  A. V. Ivanov  L. Z. Reznitskii  V. G. Belichenko  C. -H. Hung  S. -L. Chung  Yo. Iizuka  K. -L. Wang 《Doklady Earth Sciences》2011,441(1):1498-1501

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Sedimentary complexes of the cover of the Dzabkhan continental block: Different sedimentary basins and source areas     

E. F. Letnikova  I. A. Vishnevskaya  F. A. Letnikov  N. I. Vetrova  S. I. Shkolnik  Yu. A. Kostitsyn  E. A. Karakovskii  L. Z. Reznitskii  N. A. Kanygina 《Doklady Earth Sciences》2016,470(2):1071-1075

The geochemical and Sm–Nd isotope characteristics of Late Precambrian and Early Cambrian sandstones previously related to the sedimentary cover of the Dzabkhan continental block are reported. It is established that the Riphean and Vendian sedimentary rocks of the Ul’zitgol’skaya and Tsaganolomskaya Formations were accumulated within the Dzabkhan continental block as a result of recycling of the terrigenous deposits formed at the expense of destruction of basement rocks and younger granite. The formation of terrigenous rocks of the Bayangol’skaya Formation after a gap in sedimentation occurred in the sedimentary basin, where only the Late Riphean formations of the juvenile crust, probably of the Dzabkhan–Mandal block were the sources, without the contribution of the ancient crustal material. The Tsaganolomskaya and Bayangol’skaya Formations were formed in different sedimentary basins and cannot be related to the same complex.  相似文献