ZIRCON U-Pb CHRONOLOGY OF QUARTZ MONZOPORPHYRY IN JIAWULA Pb-Zn-Ag DEPOSIT, DAXINGANLING MOUNTAINS: Geological Implications

The Jiawula Pb-Zn-Ag Deposit, one of the large-scale deposits in the Derbugan Cu(Mo)-Ag-Pb-Zn metallogenic belt in the western slope of Daxinganling Mountains, genetically has long been considered as epithermal type related to volcanic-subvolcanic hydrothermal process. The chronology of ore-bearing quartz monzoporphyry is studied on the basis of field investigation. The results show that the LA-ICP-MS zircon U-Pb is dated 152.2±1.5 Ma. Combined with previous diagenetic and metallogenic chronology researches, it is thought that the Jiawula Deposit was formed in Late Jurassic to the early stage of Early Cretaceous, contemporaneous with similar deposits in the region, which is a product of post-collisional orogeny extensional tectonic setting after the closure of Mongolia-Okhotsk Ocean.