Geologic position,age, and petrogenesis of plagiogranites in northern Rudny Altai |
| |
| Authors: | ML Kuibida NN Kruk OV Murzin SP Shokal’skii NI Gusev TI Kirnozova AV Travin |
| |
| Institution: | 1. V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Koptyuga 3, Novosibirsk, 630090, Russia;2. Siberian Research Institute of Geology, Geophysics and Mineral Resources, Krasnyi pr. 67, Novosibirsk, 630091, Russia;3. A.P. Karpinsky Russian Geological Research Institute, Srednii pr. 74, St. Petersburg, 199106, Russia;4. V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry, ul. Kosygina 19, Moscow, 119991, Russia |
| |
| Abstract: | The geologic position, age, petrologic composition, and petrogenesis of mesoabyssal plagiogranites in northern Rudny Altai, dated earlier at the Early–Middle Devonian, are considered. The Middle Carboniferous (322–318 Ma) age of granitoids has been substantiated by isotope-geochronological data (U–Pb zircon dating and Ar–Ar amphibole and biotite dating). Geologic-structural studies showed that the intrusion of granitoids took place at the time when compression was changed by sinistral faulting. This led to the conclusion that the granitoids formed at the peak of the collision between the Siberian and the Kazakhstan paleocontinents. Geochemical and isotope studies showed that most of the analyzed plagiogranites belong to high-alumina (continental) type and resulted from the deep melting (~ 15 kbar) of metabasic substrates compositionally similar to N-MORB (judging from results of geochemical modeling and the Nd isotope composition). The presence of plagiogranites of low-alumina (oceanic) type in the postgranite dike series testifies to the melting of the Rudny Altai heterogeneous crust at different depths during its collisional thickening. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
