The role of island-arc oceanic, collisional and intraplate magmatism in the formation of continental crust in the Mongolia-Trasnbaikalia region: geostructural, geochronological and Sm-Nd isotope data

• Published in: Geodynamics & Tectonophysics
• Main Authors: I. V. Gordienko, И. В. Гордиенко
• Other Authors: The study was financially supported by the Earth Sciences Department of the Russian Academy of Sciences (Programme IX.124.1 – Deep Geodynamics and Evolution of the Lithosphere: Regularities in the Occurrence of Mantle Plumes and Plate Tectonic Processes, Dynamics of Sedimentary Basins (Coordinator: Academician of RAS N.L. Dobretsov), the Laboratory of Geodynamics, Geological Institute SB RAS (Budget Item IX.124.1.1, State No. АААА-А17-11701160013-4), and the Russian Foundation for Basic Research (projects 15-05-01633а and 19-05-00312а) (Project Leader: Corresponding Member of RAS I.V. Gordienko)., Исследования выполнены при финансовой поддержке Отделения наук о Земле РАН по программе IX.124.1. «Глубинная геодинамика и эволюция литосферы: закономерности проявления мантийных плюмов и плитотектонических процессов, динамика осадочных бассейнов» (координатор акад. РАН Н.Л. Добрецов), бюджетной темы лаборатории геодинамики ГИН СО РАН IX.124.1.1. (гос. номер АААА-А17-11701160013-4) и РФФИ (проекты № 15-05-01633а, 19-05-00312а) (рук. чл.-корр. РАН И.В. Гордиенко).
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Institute of the Earth's crust of the Russian Academy of Sciences, Siberian Branch 2021
• Subjects: континентальная кора; oceanic crust; island arc; accretion; collision; intraplate magmatism; Sm-Nd model age; source; isotope province; continental crust; океаническая кора; островная дуга; аккреция; коллизия; внутриплитный магматизм; Sm-Nd модельный возраст; источник; изотопная провинция; karelian
• Online Access: https://www.gt-crust.ru/jour/article/view/1162; https://doi.org/10.5800/GT-2021-12-1-0510

The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify the mechanisms of interactions between the crust and the mantle in the development of the Neoarchean, Proterozoic and Paleozoic magmatic and sedimentary complexes in the study area. Using the results of his own studies conducted for many years and other published data on this vast region of Central Asia, the author have analysed compositions, ages and conditions for the formation of Karelian, Baikalian, Caledonian and Hercynian structure-formational complexes in a variety of geodynamic settings. Based on the geostructural, petrological, geochemical, geochronological and Sm-Nd isotope data, he determines the crustal and mantle sources of magmatism, conducts the identification and mapping of isotopic provinces, and reveals the role of island-arc oceanic, accretion-collision and intraplate magmatism in the formation of continental crust. Considering the formation of the bulk continental crust, three main stages are distinguished: (1) Neoarchean and Paleoproterozoic (Karelian) (almost 30% of the crust volume), (2) Meso-Neoproterozoic (Baikalian) (50%), and (3) Paleozoic (Caledonian and Hercynian) (over 20%). This sequence of the evolution stages shows the predominance of the ancient crustal material in igneous rocks sources at the early stage. During the subsequent stages, tectonic structures created earlier were repeatedly reworked, and mixed crustal-mantle and juvenile sources were widely involved in the formation of the bulk continental crust in the study area. Целью данного фундаментального исследования являлось изучение процессов формирования континентальной коры Монголо-Забайкальского региона. Главной задачей было выявление механизмов корово-мантийного взаимодействия в процессе массового образования неоархей-протерозой-палеозойских магматических и осадочных комплексов при становлении континентальной коры. В результате многолетних исследований автора в обширном регионе Центральной Азии был проанализирован ...