Terrain tectonics of the Central Asian folded beltстатья из журнала
Аннотация: The terrain analysis concept envisages primarily a possibility of approximation of fragments / terrains of various geodynamic settings which belong to different plates.The terrain analysis can supplement the theory of plate tectonics in solving problems of geodynamics and tectonics of regions of the crust with complex structures.The Central Asian belt is among such complicated regions.Terrain structures occurred as a result of combined movements in the system of 'frontal' and/or oblique subduction -collision.In studies of geological objects, it is required first of all to prove their (vertical and horizontal) autochthony in relations to each other and then proceed to paleogeodynamic, paleotectonic and paleogeographic reconstructions.Obviously, such a complex approach needs data to be obtained by a variety of research methods, including those applied to study geologic structures, stratigraphy, paleontology, paleogeography, lithothlogy, geochemistry, geochro nology, paleomagnetism etc.Only by correlating such data collected from interdisciplinary studies of the regions, it is possi ble to establish reliable characteristics of the geological settings and avoid mistakes and misinterpretations that may be asso ciated with the 'stratigraphic' approach to solutions of both regional and global problems of geodynamics and tectonics of folded areas.The terrain analysis of the Central Asian folded belt suggests that its tectonic structure combines marginal continental rock complexes that were formed by the evolution of two major oceanic plates.One of them is the plate of the PaleoAsian Ocean.As the analogue of the current IndoAtlantic segment of Earth, it is characterised by the presence of continental blocks in the composition of the oceanic crust and the formation of oceanic basins resulting from the breakup of Rodinia and Gondvana.In the course of its evolution, supercontinents disintegrated, and the blocks were reunited into the Kazakhstan Baikal continent.The base of the KazakhstanBaikal continent was formed in the VendCambrian due to subduction of the oceanic crust of the PaleoAsian Ocean, including the Precambrian microcontinents and terrains of the Gondvana group, underneath the southeastern margin of the Siberian continent (in the current coordinates).Due to subduction followed by collision of the microcontinents with the KazakhstanTuvaMongolia island arc, the crust had consolidated, and a complex continent was formed.Another major plate is the plate of the PaleoPacific Ocean.It is characterized by the longterm tectonomagmatic evolu tion without any involvement of the continental crust and by complex processes of the formation of the continental margins.Its evolution resulted in the formation of the VendPaleozoic continental margin complexes of the western segment of the Siberian continent which comprise the VendCambrian KuznetskAltai island arc and a complex of rocks of the Ordovic Early Devonian passive margin and the DevonEarly Carbonic active margin.In the accretional wedges of the Kuznetsk Altai island arc, abundant are only fragments of the VendEarly Cambrian oceanic crust including ophiolites and paleo oceanic uplifts.The contemporary analogue of the Central Asian folded belt is the southeastern margin of Asia, represented by the junction area of the IndoAustralian and Pacific plates.
Год издания: 2014
Авторы: M.M. Buslov
Издательство: Institute of the Earth's crust, Siberian Branch of RAS
Источник: Geodynamics & Tectonophysics
Ключевые слова: Geological Studies and Exploration, Mining and Gasification Technologies, Geochemistry and Geologic Mapping
Другие ссылки: Geodynamics & Tectonophysics (PDF)
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DOAJ (DOAJ: Directory of Open Access Journals) (HTML)
Geodynamics & Tectonophysics (HTML)
DOAJ (DOAJ: Directory of Open Access Journals) (HTML)
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Том: 5
Выпуск: 3
Страницы: 641–665