The Chelkar Peridotite-Gabbronorite Pluton (Kokchetav Massif, Northern Kazakhstan): Formation Type and Geochronology

摘要

The occurrence of large plutons composed of ultra-mafic, mafic, and alkaline rocks is a peculiar feature of many Precambrian sialic massifs in Kazakhstan. They are known in the Kokchetav, Shatsky, Ulutau, and Erementau-Niyaz massifs [ 1, 3, 5, 6, 8]. Their maximal number is characteristic of the Kokchetav massif of northern Kazakhstan, where they are united into the Zlatogorsk peridotite-pyroxenite-norite and Krasnyi Mai alkaline ultramafic complexes [5, 8]. The petrotypical Zlatogorsk pluton composed of various ultramafic and mafic rocks ranging from anorthosites and dunites to anorthosites and leu-conorites is now the best investigated intrusion among plutons belonging to the peridotite-pyroxenite-norite complex.