Литосфера (Apr 2018)
Kazakhstan and Tarim microcontinents on the Devonian paleotectonic reconstructions
Abstract
Devonian latitudes of the Kazakhstan and Tarim microcontinents obtained from paleomagnetic data. Definition based on the results of the study pre-folded high-temperature components of magnetization of rocks. The article uses the results of paleomagnetic studies of Devonian sedimentary and magmatic rocks, which formed on the continental crust. In these studies, conducted by various researchers, the high-temperature pre folded primary component of magnetization detected in Devonian rocks on 19 plots. Based on that data the latitude of 24.6 ± 5.5° determined for the Center of Kazakhstan microcontinent in the Early-Middle Devonian and 22.7 ± 4.6° in the Late Devonian. The Early-Middle Devonian latitude 6.1 ± 4.2° determined for the Сenter of the Tarim microcontinent. A significant number of paleotectonic schemes of Asia with different design and detail were proposed. We reviewed the position of the Kazakhstan and Tarim microcontinents in 19 paleo-tectonic reconstructions published after 2000. There are three groups of paleoreconstructions among them. On many reconstructions, the location of continental terranes and island arcs of Kazakhstan and Central Asia in the Early and Middle Paleozoic resembles the modern structure of the Indonesian region. On other reconstructions, these terranes form an arc that connected two paleocontinents in the Paleozoic - the Baltic and the Siberian ones. In the alternative design of reconstructions, the terranes have a relatively isolated position in the Paleoocean. As a result, а way of for co-ordination of matching paleotectonic reconstructions with paleomagnetic data is proposed.
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