U‒Pb Age and Chemical Characteristics of Ti-Rich Andradites from Vein Calcite–Silicate Rocks of the Akhmatovskaya and Perovskitovaya Mines in the South Urals
摘要
The U–Pb (ID-TIMS) age has been determined for the first time for the Ti-rich andradites (319 ± 1 Ma) from calcite-silicate vein rocks uncovered by the Akhmatovskaya and Perovskitovaya mines at the contact zone of Precambrian gabbroids of the Kusa–Kopan intrusive complex and carbonate rocks of the Satka Formation in the South Urals. The mineral association of vein calcite-silicate rocks corresponds to rodingites. The U‒Pb age of garnets from the veins coincides with the stage of the most intense fold-and-thrust deformations in the area of the Main Uralian Fault and Magnitogorsk zone, namely, 335–285 Ma. New geochronological data indicate a complex multistage history of mineralization of silicate-carbonate rocks at the contact zone of Kusa–Kopan gabbroids and Riphean carbonates.