首页 | 本学科首页   官方微博 | 高级检索  
     


Continental crust in Gorny Altai: nature and composition of protoliths
Authors:N.N. Kruk  A.G. Vladimirov  G.A. Babin  S.P. Shokalsky  N.V. Sennikov  S.N. Rudnev  N.I. Volkova  V.P. Kovach  P.A. Serov
Affiliation:1. V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, prosp. Akad. Koptyuga 3, Novosibirsk, 630090, Russia;2. Siberian Research Institute of Geology, Geophysics, and Mineral Resources, Krasnyi prosp. 67, Novosibirsk, 630091, Russia;3. A.P. Karpinsky Russian Geological Research Institute, Srednii prosp. 74, St. Petersburg, 199106, Russia;4. A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, prosp. Akad. Koptyuga 3, Novosibirsk, 630090, Russia;5. Institute of Precambrian Geology and Geochronology, nab. Makarova 2, St. Petersburg, 199034, Russia;6. Geological Institute, Kola Scientific Center, ul. Fersmana 14, Apatity, 184200, Russia
Abstract:The history of the Vendian–Early Paleozoic formation of protoliths of continental crust in the Gorny Altai segment of the Central Asian fold belt is considered, and their composition, isotopic characteristics, and formation mechanisms are estimated. We have established two stages of crust-forming processes in Gorny Altai: Early and Late Caledonian, with the different structures of formed geoblocks and nature and compositions of crustal protoliths. At the Early Caledonian stage, fragments of oceanic lithosphere of basic composition (MORB, OIT, OIB) (TNd(DM-2st) = 0.65–1.1 Ga) formed, as well as island arcs with andesite-basaltic and andesitic protoliths with low contents of incompatible elements (TNd(DM-2st) = 0.7–0.9 Ga). At the Late Caledonian stage, the redistribution of the substance of these blocks and the external supply of material led to the formation of heterogeneous crust of turbidite basins with an oceanic basement and andesite-dacitic upper-crustal protoliths (TNd(DM-2st) varies from 0.8–0.9 Ga in the framing of the volcanic arc of Altaids to 1.4–1.6 Ga at the boundary of the Altai–Mongolian microcontinent).
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号