Early Permian Gabbro-granite Magmatism in Southern Rudny Altai: First U–Pb Geochronological and Geochemical Data
摘要
The manifestation of Early Permian intrusive magmatism in the territory of Rudny Altai have proven for the first time by geochronological methods (U–Pb LA-ICP-MS dating of magmatic zircon). It is represented by two associations: gabbro-diorite-syenite-granite-leucogranites with an age of 300–298 Ma (Bedarevka and Orlovka massifs) and granite-leucogranites with an age of 293–286 Ma years (Verkhne-Cheremshanka massif). The gabbro and diorites have geochemical features similar to intraplate basalts and can be compared with synchronous basites of the Mirolyubovka dyke complex in the nearboring Kalba-Narym terrane. The granitoids have geochemical features close to those of A-granites. The generation of granitic magmas is most likely the result of partial melting of lower- and middle- crustal sources under the effect of mafic magmas. Analysis of geological and geochemical data allows to conclude that the Early Permian gabbro-granite magmatism in Rudny Altai may be associated with the Tarim Large Igneous Province, associated with the mantle plume.