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Paleoproterozoic accretion in the Northeast Siberian craton: Isotopic dating of the Anabar collision system 总被引：1，自引：0，他引：1
O. M. Rosen L. K. Levskii D. Z. Zhuravlev A. Ya. Rotman Z. V. Spetsius A. F. Makeev N. N. Zinchuk A. V. Manakov V. P. Serenko 《Stratigraphy and Geological Correlation》2006,14(6):581-601
Geochronological database considered in the work and characterizing the Anabar collision system in the Northeast Siberian craton includes coordinated results of Sm-Nd and Rb-Sr dating of samples from crustal xenoliths in kimberlites, deep drill holes, and bedrock outcrops. As is inferred, collision developed in three stages dated at 2200–2100, 1940–1760, and 1710–1630 Ma. The age of 2000–1960 Ma is established for substratum of mafic rocks, which probably originated during the lower crust interaction with asthenosphere due to the local collapse of the collision prism. Comparison of Sm-Nd and Rb-Sr isochron dates shows that the system cooling from ≈700 to ≈300°C lasted approximately 300 m.y. with a substantial lag relative to collision metamorphism and granite formation. It is assumed that accretion of the Siberian craton resulted in formation of a giant collision mountainous structure of the Himalayan type that was eroded by 1.65 Ga ago, when accumulation of gently dipping Meso-to Neoproterozoic (Riphean) platform cover commenced. 相似文献
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A. B. Makeev T. B. Bayanova S. E. Borisovsky O. M. Zhilicheva 《Geology of Ore Deposits》2016,58(8):646-652
This study focuses on the morphological features, color cathodoluminescence, chemical composition, age, and source of zircons from the Ichet’yu occurrence. The isotopic U–Pb age of Paleo–Mezoproterozoic zircon grains varies within an interval of ~700 Ma from 2247 to 1478 Ma. The average roundness and well-preserved integrity of zircon grains allow us to suggest their proximal source. The available data show that the basement of the Middle Timan, composed of continental Paleo–Mezoproterozoic igneous rocks, is the most probable source of zircon in the Ichet’yu occurrence. These rocks are apparently a continuation of the Archean–Proterozoic Arkhangel’sk Mobile Belt. 相似文献
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N. V. Makarova V. M. Makeev T. V. Sukhanova P. S. Miklyaev A. L. Dorozhko I. V. Korobova 《Moscow University Geology Bulletin》2012,67(4):209-217
The neotectonic structures of the Lower Oka (Nizhneokskii) Region formed under different geodynamic conditions. This is attested by the morphology, orientation, internal structure, and jointing of the structures. The Oka-Tsna arc formed under the effect of tension from an inner source on the one hand and stress from the Alpian belt on the other hand. The latitudinally-oriented structures of the northwestern slope of the Tokmovo arc emerged as a result of uplift and widening. Both types of structure are combined within the limits of the Oka-Murom trough, which is a geodynamically active zone. 相似文献
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Metal films on the surfaces and within diamond crystals from Arkhangelskaya and Yakutian diamond provinces 总被引：2，自引：0，他引：2
Representative samples of diamonds from five kimberlite pipes (Lomonosovskaya, Archangel’sk, Snegurochka, XXIII Congress of the Communist Party of the Soviet Union (CPSU), and Internationalnaya) of the Arkhangelskaya and Yakutian diamond provinces in Russia have been studied. Thirty-three varieties of metal films have been identified as syngenetic associated minerals. The films consist of 15 chemical elements that occur in the form of native metals and their natural alloys. Remnants of metal films were detected within diamond crystals. The metal films coating diamonds are a worldwide phenomenon. To date, these films have been described from Europe, Asia, South America, and Africa. Native metals, their alloys, and intermetallides are actual companion minerals of diamond. 相似文献
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V. A. Matrenichev N. A. Alfimova O. A. Levchenkov V. M. Savatenkov B. V. Belyatskii M. M. Astaf’eva A. F. Makeev S. Z. Yakovleva 《Stratigraphy and Geological Correlation》2011,19(6):579-599
New data on the stratigraphy and isotopic age of supracrustal rocks from the lower part of the section constituting the northeastern limb of the Lekhta structure (northern Karelia) and their relationships with the basement are considered. Geological-petrographic, lithological-geochemical, and isotopic data are used to define three formations united into the Okhta Group. Immediate relationships between volcanics of the greenstone belt and granitoids of the basement represented by the oldest (for the Baltic Shield: 2.8 Ga) continental weathering crust after granites, are discussed. Isotopic age of volcanics and granite gneisses of the basement indicates that the Lopian supracrustal complex of the Lekhta structure was deposited in a period lasting 16 myr with duration of periods corresponding to formation of the Okhta and Pebozero groups being as long as 8 and 11 myr, respectively. In the regional stratigraphic scale, the entire Archean part of the supracrustal section in the Lekhta structure should be attributed to the Middle Lopian. 相似文献
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