INTERNAL STRUCTURE, GEODYNAMIC SETTING, AND U-Pb ISOTOPIC AGE OF THE KUBADRU GRANITOID BATHOLITH (Gorny Altai)
N.N. Kruk, A.G. Vladimirov, S.N. Rudnev, V.G. Vladimirov, Ya.V. Savinykh, O.A. Levchenkov*, V.P. Kovach**, and A.D. Kireev**
Institute of Geology, Siberian Branch of the RAS, 3 prosp. Koptyuga, Novosibirsk, 630090, Russia
* Institute of Geology and Geochronology of the Precambrian, Russian Academy of Sciences, 2 nab. Makarova, 119034, St. Petersburg, Russia
** United Institute of Geology, Geophysics and Mineralogy, Siberian Branch of the RAS 3 prosp. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Geodynamics, granitoid magmatism, petrochemistry, geochemistry, U-Pb and Sm-Nd isotope methods
Pages: 645-659
Abstract
The mesoabyssal Kubadru batholith resulted from collisional incorporation of the Chulyshman terrane in the West Sayan structure. The turbidite strata making up the basement of the Teletskoe block were, most likely, a protolith for the batholith granitoids. The U-Pb age of zircons from granitoids of major phase is 373.3  6.5 Ma, which permits correlation of the Kubadru batholith with abundant Late Devonian-Early Carboniferous granitoid plutons in Gorny Altai (Yaloman, Talitsa, etc.) and in the zone of its junction with the West Sayans (Altyntau and Teletskoe-Bashkaus belts). The Kubadru mass is made up of bimodal calc-alkalic rock series. The intrusion and formation of some melt portions (from gabbroids to granite-leucogranites) took place against the background of intense sinistral shearing strains. The mass has a strongly asymmetric internal structure: The western flank is an exposed root zone, which formed during viscoplastic sinistral shearing strains, and the eastern flank is composed of intrusive granitoids, which, most likely, resulted from intense shear compression and extrusion of magma accompanied by the formation of a gentle granitoid body. |
