Fluid Inclusions of the Changgou Gold Deposit in North Hanyin, South Qinling

The Changgou gold deposit is located in northern Hanyin, South Qinling orogenic belt, and the ore body is mainly controlled by ductile shear zone. The fluid inclusions of two stages quartz veins in the Changgou gold deposit have been studied. The results indicated that these inclusions are mainly gas-liquid inclusions in quartz veins, with few single phase and three-phase fluid inclusions. Their homogeneous temperature range from 175℃ to 385℃, and the ones of fluid inclusions in gold-bearing quartz veins are 190~210℃. Their salinities vary from 0.88% NaCleq to 19.05% NaCleq. These metallogenic fluids have the features of medium-low temperature and medium-low salinity. The fluid trapping pressures of quartz veins in S₂ stage are 45.59~85.00Mpa, with trapping depth of 1.69~3.15km, belonging to middle-shallow depth mineralization. The quartz veins in S₂ are closely related to gold mineralization, but the quartz veins in S₃ stage show high temperature and medium-low salinity, have little relationship with mineralization.