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

The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify mechanisms interactions between and mantle development Neoarchean, Proterozoic Paleozoic magmatic sedimentary complexes study area. Using results his own studies conducted for many years other published data on this vast Central Asia, author have analysed compositions, ages conditions Karelian, Baikalian, Caledonian Hercynian structure-formational a variety geodynamic settings. Based geostructural, petrological, geochemical, geochronological Sm-Nd isotope data, he determines crustal sources magmatism, conducts identification mapping isotopic provinces, reveals role island-arc oceanic, accretion-collision intraplate magmatism crust. Considering bulk crust, three main stages are distinguished: (1) Neoarchean Paleoproterozoic (Karelian) (almost 30% volume), (2) Meso-Neoproterozoic (Baikalian) (50%), (3) (Caledonian Hercynian) (over 20%). This sequence evolution shows predominance ancient material igneous rocks at early stage. During subsequent stages, tectonic structures created earlier were repeatedly reworked, mixed crustal-mantle juvenile widely involved