Geochemical Characteristics and Prospecting Significance of the Granites from the Duobagou Gold Deposit in the Southeast Tarim Basin

The Duobagou gold deposithas been newly discovered in the southeastern margin of Tarim Basin witha certain scale, and the gold orebodies were mainly occurred in the tectonic alteration zone of tonalite that intrude into the diorite.In this paper, the petrological and geochemical features of diorite, tonalite and gold ore have been studied.The results show that the diorite has the properties of adakitic rocks, while the tonalite has the characteristics of the Himalayan type granite, and the δ¹⁸O_V-SMOW values of whole rocks range from 11.0‰ to 13.4‰. The LA-ICP-MS zircon U-Pb dating for gold ore has revealed multiphase peak metamorphism age, the obtained ²⁰⁶Pb/²³⁸U ages vary from 422 Ma to 1284 Ma, suggesting that the diorite and tonalite were formed at (497±13)Ma and (435.9±6.6)Ma, respectively. Followed the age of the tectonic hydrothermal activity, the metallogenetic age is later than the formation age of tonalite. The ages of two-phases magma activities in this mining area are consistent with two main metallogenic stages of Southeast Tarim-North Alty in Early Paleozoic.The formation of Duobagou gold deposit had correlation with the second metallogenic stages, indicating that there is certainly potential to discover Au-Cu deposits related adakitic and Himalayan-type granites in Southeast Tarim Basin.