Zircon SHRIMP U-Pb Age of the Binggounan Magmatic Ni-Cu Deposit in East Kunlun Mountains and Its Tectonic Implications

The Binggounan mafic-ultramafic intrusion is located in the East Kunlun orogenic belt that belongs to the southwestern margin of Qaidam basin and adjacent to the Kunbei fault. This intrusion is mainly made up of olivine-pyroxenite, gabbro, diorite and diabase dykes, but the orebodies only occur in the olivine-pyroxenite. Petrologic and geochemical characteristics show that the Binggounan mafic-ultramafic intrusion was a ferruginous series mafic-ultramafic intrusive body and the deposit belongs to magmatic segregation sulfide Cu-Ni deposit. The SHPIMP U-Pb age (377.8±3.4 Ma) of the zircons in the olivine-pyroxenite indicates that it is a relatively young Cu-Ni deposit in the East Kunlun orogenic belt. The rocks in the deposit have positive ΕNd(t) values ranging from +2.35 to +3.81 and (87Sr/86Sr)i from 0.7057 to 0.7105, indicating that the magma have experienced some contamination of the surrounding rocks which probably led to the sulfur saturation and then the immiscible of the sulfides. The Binggounnan Cu-Ni deposit perhaps is a product in the post-collision tectonic setting, which is different from the Xiarihamu Cu-Ni deposit. Therefore, the study is of significant implication for the exploration of Cu-Ni deposits in the East Kunlun orogenic belt. © 2017, Science Press. All right reserved.