Permian ultramafic-mafic magmatism and accompanying Cu-Ni mineralization in the Gobi-Tien Shan belt as a result of the Tarim plume activity

摘要

The paper reports data on the age, composition, and geodynamic environments of Permian ultramafic-mafic complexes in the Zaisan-Gobi zone in the eastern Gobi-Tien Shan rift belt. The synchronous formation of these complexes with Early Permian lava alkali and tholeiitic basalts discovered beneath the cover of the Tarim and Junggar platform blocks suggests that they are derivates of the Tarim plume related to the Permo-Triassic Siberian superplume. This is evidenced from the composition and metallogeny of the complexes similar to those of magnesian trap intrusions on the western periphery of the Siberian Platform. In the area of influence of the Tarim plume, including the Zaisan-Gobi zone and other structures of the Gobi-Tien Shan belt, diverse Cu-Ni-PGE, Ni-Co-As, Au-Hg, Cu-Mo, and ore deposits related to plume magmatism formed. Their composition, formation conditions, and relationship with magmatism are discussed.