Geochemical Characteristics of Granites from the Jiangjunzhai Tungsten Deposit of Southeast Hunan Province and Its Re-Os Isotopic Dating

The Jiangjunzhai tungsten deposit is a typical quartz-wolframite deposit in Baiyunxian ore field. The granite body in the Jiangjunzhai tungsten deposit is a compound rockmass,which has the features of crust-derived type granite and is the product of comagmatic evolution. In this paper,the geochemical characteristics of granite in Jiangjunzhai tungsten deposit and the Re-Os isotopic dating of molybdenite from quartz-wolframite veins were studied and carried out,in order to elucidate the timing of mineralization and reveal the time limites and geodynamic setting of large-scale metallogeny in Southeast Hunan. Re-Os dating for four molybdenites yields a model age of (151.3±2.5) Ma~(163.6±2.3) Ma and an isochron age of (169.6±2.7) Ma,indicating that the Jiangjunzhai tungsten deposit was formed in the Early Yanshanian period and is the result of large scale mineralization in South China.