Tectonic reconstruction of Uda-Murgal arc and the Late Jurassic and Early Cretaceous convergent margin of Northeast Asia–Northwest Pacific
1Geological Institute of the Russian Academy of Sciences (GIN RAN), Pyzhevsky Pereulok 7, Moscow, 109017, Russia
2Rusneftegaz Co., Altufiev street 2a, Moscow, 127273, Russia
3St. Petersburg State University, Geological Department, Universitetskaya nab. 7/9, St. Petersburg, 199034, Russia
4Geophysical Institute, University of Alaska Fairbanks, Fairbanks, USA
Abstract. A long tectonic zone composed of Upper Jurassic to Lower Cretaceous volcanic and sedimentary rocks is recognized along the Asian continent margin from the Mongol-Okhotsk fold and thrust belt on the south to the Chukotka Peninsula on the north. This belt represents the Uda-Murgal arc, which was developed along the convergent margin between Northeast Asia and Northwest Meso-Pacific. Several segments are identified in this arc based upon the volcanic and sedimentary rock assemblages, their respective compositions and basement structures. The southern and central parts of the Uda-Murgal arc were a continental margin belt with heterogeneous basement represented by metamorphic rocks of the Siberian craton, the Verkhoyansk terrigenous complex of Siberian passive margin and the Koni-Taigonos Late Paleozoic to Early Mesozoic island arc with accreted oceanic terranes. At the present day latitude of the Pekulney and Chukotka segments there was an ensimatic island arc with relicts of the South Anyui oceanic basin in a backarc basin. Accretionary prisms of the Uda-Murgal arc and accreted terranes contain fragments of Permian, Triassic to Jurassic and Jurassic to Cretaceous (Tithonian–Valanginian) oceanic crust and Jurassic ensimatic island arcs. Paleomagnetic and faunal data show significant displacement of these oceanic complexes and the terranes of the Taigonos Peninsula were originally parts of the Izanagi oceanic plate.
Sokolov, S. D., Bondarenko, G. Ye., Khudoley, A. K., Morozov, O. L., Luchitskaya, M. V., Tuchkova, M. I., and Layer, P. W.: Tectonic reconstruction of Uda-Murgal arc and the Late Jurassic and Early Cretaceous convergent margin of Northeast Asia–Northwest Pacific, Stephan Mueller Spec. Publ. Ser., 4, 273-288, doi:10.5194/smsps-4-273-2009, 2009.