Stephan Mueller Special Publication Series www.stephan-mueller-spec-publ-ser.net 1868-4556 1868-4564 4 Geology, geophysics and tectonics of Northeastern Russia: a tribute to Leonid Parfenov 2009 10.5194/smsps-4-65-2009 http://www.stephan-mueller-spec-publ-ser.net/4/65/2009/ http://www.stephan-mueller-spec-publ-ser.net/4/65/2009/smsps-4-65-2009.html http://www.stephan-mueller-spec-publ-ser.net/4/65/2009/smsps-4-65-2009.pdf 65 70 2009-09-17 Multi-phase tectonic structures in the collision zone of the Kolyma-Omolon microcontinent and the eastern margin of the North Asian craton, Northeastern Russia A. V. Prokopiev prokopiev@diamond.ysn.ru V. S. Oxman Diamond and Precious Metal Geology Institute, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia The sequence of formation of structures is established in the zone of junction of the eastern margin of the North Asian craton and the northeastern flank of the Kolyma-Omolon microcontinent, in the area of bend of the Kolyma structural loop. Detailed structural studies revealed two phases in the formation of Mesozoic structures – an early thrust phase and a late strike-slip phase. Structures formed during each of the phases are described. Thrust structures are represented by the Setakchan nappe on which the minimum amount of horizontal displacement is estimated at 13–15 km. Later superposed left-lateral strike-slip faults have a north strike. Formation of these latter structures occurred during the second phase of collision between the Kolyma-Omolon microcontinent and the eastern margin of the North Asian craton. Grebennikov, G. A., Epov, O. G., Boyarshinov, V. V., et al.: Geologic map of Yakutia. Lower Yana block, Scale 1:500 000, Map's Printing-house of Russian Geological Research Institute, St.-Petersburg, 1995 \mbox(in Russian). Layer, P. W., Newberry, R., Fujita, K., Parfenov, L. M., Trunilina, V. A., and Bakharev, A. G.: Tectonic setting of the plutonic belts of Yakutia, Northeast Russia, based on $^40$Ar/ $^39$Ar and trace element geochemistry, Geology, 29, 167–170, 2001. Oxman, V. S.: Tectonics of the Chersky collisional belt (northeast Asia), GEOS, Moscow, 269~pp., 2000 \mbox(in Russian). Oxman, V. S. and Prokopiev, A. V.: Terrigenous tectonic mélanges of the Polousnyy synclinorium, Otechestvennaya Geologiya, 5, 47–50, 2000 \mbox(in Russian). Parfenov, L. M.: Terranes and formation history of Mesozoic orogenic belts of east Yakutia, Tikhookean. Geol., 14(6), 32–43, 1995 \mbox(in Russian). Parfenov, L. M., Berzin, N. A., Khanchuk, A. I., Badarch, G., Belichenko, V. G., Bulgatov, A. N., Dril, S. I., Kirillova, G. L., Kuzmin, M. I., Nokleberg, W. J., Prokopiev, A. V., Timofeev, V. F., Tomurtogoo, O., and Yang, H.: A model for the formation of orogenic belts in Central and Northeast Asia, Tikhookean. Geol., 22(6), 7–41, 2003 \mbox(in Russian). Parfenov, L. M. and Kuz'min, M. I. (Eds.): Tectonics, geodynamics and metallogeny of the Sakha Republic (Yakutia), MAIK "Nauka/Interperiodica", Moscow, 571~pp., 2001 \mbox(in Russian). Passchier, C. W. and Trouw, R. A. J.: Microtectonics, Springer, Berlin, 289~pp., 1996. Prokopiev, A. V.: Verkhoyansk-Cherskiy collisional orogen, Geology of Pacific Ocean, 15, 891–904, 2000. Prokopiev, A. V., Toro, J., Miller, E. L., Wooden, J., Trunilina, V. A., and Bakharev, A. G.: Granitoids of the Main batholith belt (northeast Asia): new U-Pb SHRIMP geochronological and geochemical data, Tectonics and metallogeny of the Circum North Pacific and East Asia, Khabarovsk, Institute of Tectonics and Geophysics, 286–288, 2007 \mbox(in Russian). Prokopiev, A. V. and Kaskevich, G. E.: Strike-slip duplexes of eastern Yakutia (northeast Russia), Otechestvennaya Geologiya, 5, 44–46, 2000 \mbox(in Russian). Raymond, L. A.: Classification of mélanges, in: Mélanges: their nature, origin, significance, Geological Society of America, Special Paper 198, 7–20, 1984. Trunilina, V. A., Poev, S. P., Orlov, Yu. S., and Oxman, V. S.: Magmatism of different geodynamic environments (zone of junction of the Verkhoyansk margin of the Siberian continent and the Kolyma-Omolon microrontinent), Publishing House of Yakutian Scientific Centre, Siberian Branch, Russian Academy of Sciences, Yakutsk, 152~pp., 1999 \mbox(in Russian).