The Fluid Inclusion Characteristics and Significance of the Huaishuping Gold Depositin Song County, Henan province

The Huaishuping gold deposit is a quartz vein gold deposit, which was occurred in slowly inclined interlayer extrusion zone of Xiong'er Group. Hydrothermal ore-forming process of this deposit can be divided into three stages:stage Ⅰ-milky quartz vein-phase crumb pyrite quartz vein, stage Ⅱ-smoke gray-polymetallic sulfide phase, and stage Ⅲ-quartz-carbonate phase. Through the studies of fluid inclusion microscopic temperature measurement and Laser-Raman spectra analysis, the results show that:three types of fluid inclusions in stage Ⅰ and Ⅱ are identified as CO₂-H₂O type, pure CO₂ and NaCl-H₂O solution type,while stage Ⅲ quartz inclusions main contain the NaCl-H₂O solution type. From the metallogenic stage Ⅰ to stage Ⅲ, the homogenization temperatures of fluid inclusions are 189~439℃→145~351℃→145~267℃, while their salinities are 6.98%~10.29%→2.03%~11.71%→2.89%~15.04%. The ore-forming fluid was evolved from H₂O-NaCl-CO₂ system,which is characterized by changing from medium temperature and medium-low salinity to low temperature and salinity NaCl-H₂O system. It's determined that the ore-forming fluid was derived from magmatic hydrothermal, which has the characteristics of deep source. And then, it's suggested that the ore-forming fluid was mainly migrated in the form of Au (HS), secondly by Au₂(HS)₂S^2-.