Structural Evolution of the Elikanskiy Granite–Gneiss Swell (Western Transbaikalia)
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The Elikanskiy granite–gneiss swell represents a structure, similar to Late Mesozoic Cordilleran-type metamorphic core complexes allocated within the Eravninskiy terrane of the Yenisei-Transbaikal tectonic collage, the Mongolo-Okhotskiy orogenic belt and a northern part of the Argun–Idermeg superterrane of the Central Asian orogenic belt. The main elements of a geological structure of the Elikanskiy metamorphic core complex are the detachment zone, core and upper nappe. The detachment zone separating a core from the upper nappe is represented by a thick zone of blastomylonites and a zone of chlorite breccias. That zone was formed under the conditions of tangential stress and led to the exhumation and structural and metamorphic transformations of magmatic rocks of the Bukhtochinskiy Complex and metamorphic rocks of the Upper Olekma Complex, which compose the core of the considered structure. The upper nappe consists of Jurassic and Cretaceous stratified rocks of the Kyker–Akimin and Usuglinskiy basin and the Early Paleozoic–Mesozoic volcanoplutonic complexes in its southeastern framing. The Elikanskiy metamorphic core complex is a part of a huge belt of metamorphic core complexes which is traced along the northern border of the Mongolo-Okhotskiy orogenic belt on distance about 2000 km. The formation of the Elikanskiy metamorphic core complex as well as other similar complexes in the eastern part of the Central Asian orogenic belt is connected with collapse of the Late Mesozoic orogen which has resulted from the accretionary and collision events connected with closing of the Mongolo-Okhotskiy paleoocean basin and respectively formation of the Mongolo-Okhotskiy orogenic belt.
Keywords:structural evolution Elikanskiy granite–gneiss swell West Stanovoy terrane Central Asian orogenic belt metamorphic core complexes
The geological studies of the Kyker–Akimin and Usugli troughs and structural studies of the Elikan granite gneiss arch were supported by the Russian Science Foundation, projects no. 16-17-10180 and 14-27-00103, respectively.
- 1.Geological Map of Chita Oblast, Scale 1 : 500 000, Ed. by I. G. Ruthshtein and N. N. Chaban (MPGiT, Moscow, 1992).Google Scholar
- 2.State Geological Map of Russian Federation, Scale 1 : 1 000 000 (Third Generation). Aldan–Transbaikalian Series, Sheet N-50 (Sretensk) (VSEGEI, St. Petersburg, 2010).Google Scholar
- 3.A. N. Efimov and T. M. Tetyaeva, Correlation and Subdivision of Precambrian and Lower Paleozoic Metamorphic Complexes in Transbaikalia (Nedra, Leningrad, 1982) [in Russian].Google Scholar
- 4.Yu. A. Zorin, V. E. Sklyarov, A. M. Mazukabzov, and V. G. Belichenko, “Metamorphic core complexes and Early Cretaceous rifting in Transbaikalia,” Geol. Geofiz. 38, 1574–1583 (1997).Google Scholar
- 5.M. E. Kazimirovskii, Candidate’s Dissertation in Geology and Mineralogy (Irkutsk, 1996).Google Scholar
- 6.A. B. Kotov, A. M. Larin, E. B. Sal’nikova, S. D. Velikoslavinskii, V. A. Glebovitskii, A. A. Sorokin, S. Z. Yakovleva, and I. V. Anisimova, “Early Cretaceous collisional granitoids of the Drevnestanovoi complex from the Selenga–Stanovoi superterrane of the Central Asian Mobile Belt,” Dokl. Earth Sci. 456, 649–654 (2014).CrossRefGoogle Scholar
- 7.A. M. Larin, E. B. Sal’nikova, A. B. Kotov, V. P. Kovach, A. A. Sorokin, A. P. Sorokin, and I. V. Anisimova, “Age and sources of volcanic rocks in the Usugli depression, East Transbaikalia,” in Geodynamic Evolution of the Lithosphere of the Central Asian Mobile belt (from Ocean to Continent): Proceedings of the Meeting (Inst. Zemnoi Kory, Sib. Otd. Ross. Akad. Nauk, Irkutsk, 2016), pp. 173–174.Google Scholar
- 9.N. V. Sachunov and K. E. Rokin, Geological Map of USSR, Scale 1 : 200 000. Sheet N-50-XXVI. Explanatory Note (Gosgeoltekhizdat, Moscow, 1970).Google Scholar
- 10.V. I. Sizykh and Yu. V. Komarov, “Structure and evolution of the Olekma megaswell,” Geotektonika, No. 4, 46–55 (1993).Google Scholar
- 11.T. V. Donskaya, B. F. Windley, A. M. Mazukabzov, A. Kröner, E. V. Sklyarov, D. P. Gladkochub, V. A. Ponomarchuk, G. Badarch, M. Reichow, and E. Hegner, “Age and evolution of late Mesozoic metamorphic core complexes in southern Siberia and northern Mongolia,” J. Geol. Soc., London 165, 405–421 (2008).CrossRefGoogle Scholar
- 12.Metallogenesis and Tectonics of Northeast Asia, No. 1765 of U.S. Geol. Surv. Prof. Pap., Ed. by W. J. Nokleberg (2010).Google Scholar