Characteristics and evolution of the ore-forming fluid in the Yinzishan gold polymetallic deposit,Simao,Yunnan,China
In order to explore the gold migration and precipitation mechanisms of the Yinzishan gold polymetallic deposit,the petrographic characteristics and thermodynamics of fluid inclusions in the deposit have been studied.The results show that there are mainly vapor-liquid two-phase fluid inclusions(LV),daughter mineral-bearing multiphase fluid inclusions(LD)and single-phase inclusions(L/V)in main ore-stage minerals of the Yinzishan gold polymetallic deposit.The ore-forming fluid is the H2O-NaCl fluid system with low to medium temperatures(140～330℃),low to medium salinities(3.23%～8.41%NaCleqv),capturing depths of 0.4～1.2 km.The temperatures,salinities and pressures of the ore-forming fluids are decreased gradually from the early stage to the late stage.The alteration mineral assemblages and the properties of ore-forming fluids indicate that the Yinzishan gold polymetallic deposit is a typical epithermal deposit,and Au was mainly migrated in the form of Au(HS)2-.In the migration process of ore-forming fluids,Au was enriched and precipitated due to the fluid-wallrock interaction and the mixing of atmospheric water and the ore-forming fluids.
Yinzishan gold polymetallic depositepithermal depositmigration and precipitation mechanisms of goldfluid inclusionore-forming fluid
NETL
NSTL
万方数据
维普
