TRACHYANDESITES OF THE MOGOT VOLCANIC FIELD (Stanovoi volcanoplutonic belt, East Siberia): AGE, GEOCHEMICAL FEATURES, AND SOURCES
I.V. Buchko1, A.A. Sorokin1, V.A. Ponomarchuk2,3, A.B. Kotov4, A.V. Travin2,5, V.P. Kovach4
1Institute of Geology and Nature Management, Far East Branch of the Russian Academy of Sciences, Relochnyi per. 1, Blagoveshchensk, 675000, Russia
2V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
3Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
4Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, nab. Makarova 2, St. Petersburg, 199034, Russia
5Tomsk State University, pr. Lenina 36, Tomsk, 634050, Russia
Keywords: North Asian craton, Stanovoi volcanoplutonic belt, Mesozoic, adakites, geochronology
Abstract
The performed 40Ar/39Ar geochronological studies yielded the first reliable age of trachyandesites of the Mogot volcanic field (115 ± 3 Ma), which, together with the age of trachyandesites of the Bomnak volcanic field (117 ± 1 Ma), gives ground to recognize a new stage (117-115 Ma) of evolution of the Stanovoi volcanoplutonic belt superposed on the igneous and metamorphic complexes of the Dzhugdzhur-Stanovoi superterrane of the Central Asian Orogenic Belt and Stanovoi structural suture. The trachyandesites of the Mogot volcanic field are similar in geochemical features to adakites. Their parental melts resulted from the transformation of Precambrian continental crust under postcollisional extension after the formation of the Mongolo-Okhotsk orogen or under sliding along the boundary between the North Asian craton and the Amur microcontinent.
|
