Re-Os geochronology and S isotope geochemistry of Dengfuxian tungsten deposit,Hunan Province,China

Dengfuxian tungsten deposit is an important deposit in Southeast Hunan Province,South China.Direct Re-Os dating of molybdenites in Dengfuxian tungsten deposit has been carried out,in order to restrict the age of mineralization.The results show that Re-Os model ages range from 149.2±2.1Ma to 156.9±2.2Ma,with an average age of 152.4±3.3Ma.All the Re-Os data define an isochron with an age of 150.5±5.2Ma,consistent with zircon U-Pb age(154.4±2.2Ma) of the Dengfuxian two-mica granite,indicating that the mineralization of the Dengfuxian tungsten deposit is genetically related to the two-mica granite.The Re contents of molybdenite range from 2.927×10-9 to 98.13×10-9,indicating that ore-forming material might have the characteristics of crustal source.The δ34S values of sulfide range from-1.36‰ to +0.61‰,implying that ore-forming material might come from the Yanshanian crust-remelting type granites.The rock-forming and ore-forming processes of Dengfuxian tungsten deposit are under a geodynamic setting of lithospheric thinning and extension,consistent with the large-scale tungsten-tin polymetallic mineralization(150~160Ma) in the Nanling Range,South China.