The Yermakovsky deposit,Western Transbaikal Region,Russia: Isotopic and geochemical parameters and sources of beryllium-bearing granitoids and other rocks |
| |
| Authors: | D A Lykhin V I Kovalenko V V Yarmolyuk A B Kotov V P Kovach |
| |
| Institution: | 1.Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry,Russian Academy of Sciences,Moscow,Russia;2.Institute of Precambrian Geology and Geochronology,Russian Academy of Sciences,St. Petersburg,Russia |
| |
| Abstract: | An isotopic study of igneous and metamorphic rocks has been carried out at the Yermakovsky bertrandite-phenakite-fluorite
deposit. It has been established that the model age of the schists pertaining to the Zun-Morino Formation is 1360–1260 Ma.
In Nd and Sr isotopic composition, these schists deviate from the isotopic composition of the continental crust and are close
in this respect to the enriched mantle reservoir (EM-II). The model age of carbonate rocks of the Zun-Morino Formation is
1330–1020 Ma. The Middle Riphean model age of the Zun-Morino Formation is interpreted as the age of its protolith. According
to the Sr and Nd isotopic data, all preore igneous rocks (granitic dikes, gabbroic rocks, and gneissose granite of the Tsagan
Complex) were formed with the participation of continental crustal material. Synore basic dikes, alkali leucogranite stock,
and syenite intrusion are considered to be mixtures of mantle components (DM+HIMU) and various continental crustal components
(Tsagan gneissose granite, crystalline schists, the mean composition of granitoids of the Angara-Vitim batholith as an estimate
of average composition of the regional continental crust). Synore igneous rocks are genetically cognate and related to the
magmatic activity in the Western Transbaikal Rift Zone presumably formed in the Triassic under effect of a mantle plume. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
