Age, sources, and geological position of anorthosites of Precambrian terranes of Central Asia: Example from the Khunzhilingol Massif, Mongolia     

I. V. Anisimova  I. K. Kozakov  V. V. Yarmolyuk  A. M. Kozlovsky  V. P. Kovach  E. A. Kudryashova  V. M. Savatenkov  L. B. Terent’eva  A. M. Fedoseenko  S. Z. Yakovleva  G. Enzhin 《Doklady Earth Sciences》2009,428(1):1120-1125

  相似文献   

Ophiolite sections of the Dzhalair-Nayman zone,South Kazakhstan: Their structure and age substantiation     

A. V. Ryazantsev  K. E. Degtyarev  A. B. Kotov  E. B. Sal’nikova  I. V. Anisimova  S. Z. Yakovleva 《Doklady Earth Sciences》2009,427(2):902-906

The ophiolite complexes outcrop extending more than 700 km in the Dzhalair-Nayman zone located between the Chuya-Kendyk Tas (in the southwest) and Aktau-Dzhungar (in the northeast) Precambrian sialic massifs in South Kazakhstan. The most complete ophiolite sections are described in the central (Andassai massif) and southeastern (Dulankara massif) parts of the zone. Plagiogranites occur in a sheeted dyke complex in the upper part of ophiolite sections. A bimodal volcanic series occurs atop the section. The U/Pb zircons ages for the Andassai and Dulankara plagiogranites are 519 ± 4 and 521 ± 2 Ma, respectively. Ophiolites associated with bimodal volcanic series are also found in the north and northeast of Kazakhstan. They may form, together with the Lower Cambrian complexes of the Dzhalair-Nayman zone, a single paleostructure, whose fragments are well-traceable for over 2000 km  相似文献   

Early Paleozoic age of gabbroids of the amur complex (Bureya-Jiamusi Superterrane of the Central Asian Fold Belt)     

A. B. Kotov  A. A. Sorokin  E. B. Sal’nikova  A. P. Sorokin  S. D. Velikoslavinskii  I. V. Anisimova  S. Z. Yakovleva 《Doklady Earth Sciences》2009,425(1):185-188

  相似文献   

Lineaments in the central part of the Moscow Syneclise and their relations to faults in the basement     

O. V. Anisimova  N. V. Koronovsky 《Geotectonics》2007,41(4):315-332

It is well known that very few young faults have been recorded within the vast territories of ancient platforms that are overlain by a virtually undeformed sedimentary cover of Phanerozoic sediments. At the same time, interpretation of topographic maps of various scales, aerial photographs, and satellite images reveals predominantly linear and occasionally arcuate zones (lineaments), some of which coincide with large fracture zones related to the Riphean rifts and grabens in the platform basement. Elevated emanations of hydrogen, radon, helium, and other gases were detected over some of the lineaments, thus indicating anomalous permeability of these zones in comparison with the adjacent areas. An opinion was stated that the elevated permeability of these fault zones is provided by block vibrations as a response to lunisolar tide effects. The lineaments are of a great environmental significance because they are conduits of groundwater migration. The origin of lineaments in the platform sedimentary cover and their relations to structural elements in the basement, to evolution, and to causes of activity have provoked great interest.  相似文献   

Age constraints and tectonic settings of metallogenic and magmatic events in the Verkhoyansk-Kolyma folded area     

A.V. Prokopiev  A.S. Borisenko  G.N. Gamyanin  G.G. Pavlova  V.Yu. Fridovsky  L.A. Kondrat’eva  G.S. Anisimova  V.A. Trunilina  A.I. Ivanov  A.V. Travin  O.V. Koroleva  D.A. Vasiliev  A.V. Ponomarchuk 《Russian Geology and Geophysics》2018,59(10):1237-1253

The paper presents new isotope geochronological data for several mineral deposits, ore occurrences, and related igneous bodies (plutons and dikes) in the Verkhoyansk-Kolyma folded area, eastern Yakutia. Twenty-one ⁴⁰Ar/³⁹Ar mica and four U-Pb zircon dates provide the first age constraints on key metallogenic units in the area. The dating results allow correlation between tectonic, magmatic, and metallogenic events. The sampled mineral deposits within the Adycha-Taryn fault zone in the southeastern Verkhoyansk-Chersky orogen apparently formed at the Jurassic-Cretaceous boundary during the final phase of the collision between the Siberian (North Asian) craton and the Kolyma-Omolon microcontinent (Kupol’noe deposit and the early metallogenic pulse of the Malotarynskoe deposit, ~ 143-144 Ma) and in the latest Early Cretaceous, in the beginning of the orogen collapse (Tallalakh and Dora-Pil’ deposits and the Malotarynskoe late metallogenic pulse, ~ 126 Ma). According to the suggested new classification of metallogenic units, these deposits belong to the Late Jurassic-Early Cretaceous Yana-Kolyma metallogenic belt. The Kyuchus deposit (~ 106 Ma), the Deputatsky ore cluster (~ 106-113 Ma), and the Khotoidokh deposit (~ 116 Ma) in the northern Verkhoyansk-Kolyma folded area belong to the North Verkhoyansk metallogenic belt. Their origin was associated with accretional and collisional processes that produced the Novosibirsk-Chukotka orogen in the middle Cretaceous. The Mangazeya ore cluster (~ 100 Ma, Early-Late Cretaceous boundary) in the southwestern end of the North Tirekhtyakh magmatic transverse belt belongs to the West Verkhoyansk metallogenic belt. The Nezhdaninskoe, Zaderzhnoe, Kurum, and Kuta deposits of the South Verkhoyansk area (~ 125-120 and ~ 100-95 Ma) can be joined into a single Verkhoyansk-Okhotsk metallogenic belt. The belt resulted from accretion and collision along the East Asian active continental margin and the related formation of the South Verkhoyansk orogen in the Early Cretaceous.  相似文献   

Tok-Algoma magmatic complex of the Selenga-Stanovoi Superterrain in the Central Asian fold belt: Age and tectonic setting     

A. B. Kotov  A. M. Larin  E. B. Salnikova  S. D. Velikoslavinskii  A. A. Sorokin  A. P. Sorokin  S. Z. Yakovleva  I. V. Anisimova  E. V. Tolmacheva 《Doklady Earth Sciences》2012,444(1):562-567

According to the results of U-Pb geochronological investigations, the hornblende subalkali diorite rocks making up the Tok-Algoma Complex in the eastern part of the Selenga-Stanovoi Superterrain of the Central Asian fold belt were formed in the Middle Jurassic rather than in the Middle Archean as was suggested previously. Thus, the age of the regional amphibolite facies metamorphism manifested itself in the Ust??-Gilyui rock sequence of the Stanovoi Complex and that superimposed on granitoids of the Tok-Algoma Complex is Mesozoic rather than Early Precambrian. The geochemical features of the Tok-Algoma granitoids are indicative of the fact that they were formed in the geodynamic setting of the active continental margin or a mature island arc. Hence, it is possible to suggest that the subduction processes along the southern boundary between the Selenga-Stanovoi Superterrain and the Mongolian-Okhotsk ocean basin in the Middle Jurassic resulted in the formation of a magmatic belt of over 500 km in length.  相似文献   

Hydrochemical Study of Academy Bay (Sea of Okhotsk)     

Tishchenko  P. Ya.  Lobanov  V. B.  Tishchenko  P. P.  Semkin  P. Yu.  Sergeev  A. F.  Anisimova  E. V.  Barabanshchikov  Yu. A.  Melnikov  V. V.  Ryumina  A. A.  Sagalaev  S. G.  Ulanova  O. A.  Shvetsova  M. G.  Shkirnikova  E. M. 《Oceanology》2022,62(1):80-92

Oceanology - The hydrological and hydrochemical data of surface and bottom waters of Academy Bay were obtained on two POI FEB RAS cruises carried out from July 11 to 14, 2016 and from September 15...  相似文献   

The age of the protolith of metamorphic rocks in the southeastern part of the Lapland granulite belt,southern Kola Peninsula: Correlation with the Belomorian mobile belt in the context of the problem of Archean eclogites     

S. P. Korikovsky  A. B. Kotov  E. B. Sal’nikova  L. Ya. Aranovich  D. I. Korpechkov  S. Z. Yakovleva  E. V. Tolmacheva  I. V. Anisimova 《Petrology》2014,22(2):91-108

U-Pb zircon isotopic data on rocks from the Kandalaksha-Umba zone of the Lapland granulite belt in the Por’ya Bay area constrain the age of the protolith of the apodacite (apotonalite) Opx-Bt granulite gneisses at 2799 ± 4 Ma, and the age of the apogabbronorite Grt-Opx-Cpx-Hbl crystalline schists at 2315 ± 23 Ma. The U-Pb sphene age of the magmatic crystallization of the postmetamorphic granodiorites is 1901 ± 5 Ma. The zircon yields the U-Pb age of the contamination of xenogenic zircons, which were captured during the dissolution of xenoliths of the host Grt-Opx-Cpx-Hbl crystalline schists in granodiorite melt. The comparison of the most important attributes of the endogenic histories of the adjacent Lapland Granulite and Belomorian Mobile belts testifies to their similar evolutionary histories: (1) the protolith age of the acid Opx-Bt granulites of the Lapland Belt (2799 ± 4 Ma) coincides with the protolith age of acid gneisses in the Belomorian Belt (2890-2690 Ma); (2) the ages of the gabbronorite protolith of Grt-Opx-Cpx-Hbl granulites in the Lapland Belt (2315 ± 23 Ma) and gabbro-anorthosite in the Kolvitsa Massif (2462-2423 Ma) are close to the protolith age of eclogitized gabbronorites in the Belomorian coronite suite (2.46–2.36 Ga); (3) the age of granulite metamorphism of acid and mafic rocks in the Lapland Belt is 1912–1925 Ma, and the age of eclogite metamorphism of gneisses and metabasites in the Belomorian Belt is approximately 1.9 Ga, i.e., their metamorphism took place in Svecofennian time; (4) the peak pressure of granulite metamorphism in the Lapland Belt was 9–11 kbar at a temperature of 800–850°C, whereas the peak metamorphic parameters of eclogite metamorphism in the Belomorian Belt were 10–12 kbar and 640–700°C. This means that the metamorphic complexes of the Lapland and Belomorian belts had the same Mezo- and Neoarchean protoliths hosting bodies of Paleoproterozoic gabbroids and were completely formed largely by a single cycle of Svecofennian high-pressure zonal metamorphism within a temperature range from the lowest grade of the eclogite to the granulite facies.  相似文献   

Early paleozoic age of the Isagachi Sequence (Chalaya Group,Gonzha Terrane) in the eastern part of the Central Asian fold belt     

A. A. Sorokin  Yu. V. Smirnov  A. B. Kotov  E. B. Sal’nikova  A. P. Sorokin  V. P. Kovach  S. Z. Yakovleva  I. V. Anisimova 《Doklady Earth Sciences》2014,457(1):810-813

  相似文献   

Metabasalts of the Bryanta sequence of the Stanovoi complex of the Dzhugdzhur-Stanovoi superterrane, Central Asian fold belt: Age and geodynamic environment of formation     

S. D. Velikoslavinsky  A. B. Kotov  E. B. Salnikova  A. A. Sorokin  A. M. Larin  S. Z. Yakovleva  V. P. Kovach  E. V. Tolmacheva  I. V. Anisimova  Yu. V. Plotkina 《Petrology》2012,20(3):240-254

In this paper, we report U-Pb geochronological, Sm-Nd isotopic, and geochemical data for the basic schists of the Bryanta sequence of the Stanovoi complex of the Dzhugdzhur-Stanovoi superterrane of the Central Asian fold belt. It was shown that the protolith of the schists was composed of island-arc subalkali basalts, which crystallized at 1933 ± 4 Ma; the age of the earliest metamorphic processes is approximately 1890?C1910 Ma. This metamorphic event could be related to the collision of the Aldan and Stanovoi continental plates or accretion-collision processes at the boundary of the Ilikan and Kupurin lithotectonic zones during the formation of the latter.  相似文献