A r– A r Ages of Hydrothermal Muscovite and Igneous Biotite at the G uposhan– H uashan District, Northeast G uangxi, South C hina: Implications for Mesozoic W – S n Mineralization

The G uposhan– H uashan district is an important W – Sn – Sb – Zn –( Cu ) metallogenic area in South C hina. It is located in the middle‐west segment of the N anling Range. Granitoids in the G uposhan– H uashan district possess certain properties of A ‐type or I ‐type granites. The W – Sn – Sb – Zn mineralization in the district is closely associated with magma emplacement. Two igneous biotite and seven hydrothermal muscovite samples from skarn, veins and greisenization ores were analyzed by A r– A r methods. Two igneous biotite samples from fine‐grained quartz monzodiorite and fine‐grained biotite granite show plateau ages of 168.7 ± 1.9 Ma and 165.0 ± 1.1 Ma, respectively. Seven hydrothermal muscovite samples from ores yield plateau ages as two groups: 165 Ma to 160 Ma and 104 Ma to 100 Ma. These data suggest that the emplacement of fine‐grained granitoids in this district is coeval with the main phase magma emplacement, different from previous studies. The W – Sn – Sb – Zn mineralization took place in two stages, i.e. the M iddle– L ate J urassic and early C retaceous. W – Sn mineralization in the G uposhan– H uashan district is closely related to the magmatism, which was strongly influenced by underplating of asthenospheric mantle along trans‐lithospheric deep faults and related fractures.