NEOPROTEROZOIC METAVOLCANOSEDIMENTARY ROCKS OF THE BOZDAK GROUP IN SOUTHERN ULUTAU (Central Kazakhstan): ISOTOPE-GEOCHEMICAL AND GEOCHRONOLOGICAL DATA
N.V. Dmitrieva1,2, E.F. Letnikova1,2, S.I. Shkol’nik3, I.A. Vishnevskaya1,2, N.A. Kanygina4, M.S. Nikolaeva1, I.V. Sharf5
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
3Institute of the Earth's Crust, Siberian Branch of the Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia
4Geological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, Moscow, 119017, Russia
5Tomsk Polytechnic University, pr. Lenina 30, Tomsk, 634050, Russia
Keywords: Late Precambrian, volcanosedimentary rocks, LA-ICP-MS zircon dating, Sm-Nd isotopes, Central Kazakhstan
Abstract
We consider geochemistry of Neoproterozoic metavolcanosedimentary rocks of the Bozdak Group in southern Ulutau (Central Kazakhstan) and present the first results of U-Pb LA-ICP-MS dating of clastic zircons and Sm-Nd isotope data. Isotope-geochemical and geochronological studies have shown that the Bozdak Group rocks resulted from the destruction of igneous and metamorphic complexes mostly of Neoproterozoic age with the participation of Archean and Paleoproterozoic rocks. The lower boundary of sedimentation is dated at 800 Ma. The obtained isotope-geochemical data on the Bozdak Group basaltoids suggest their formation on thick continental crust with the participation of subduction fluid.
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