The Dongping gold deposit is contained within an inner contacting zone of the Hercynian Shuiquangou alkali syenite. The ores occur as veins or as replacement bodies. Fluid inclusion observation shows that in early and...The Dongping gold deposit is contained within an inner contacting zone of the Hercynian Shuiquangou alkali syenite. The ores occur as veins or as replacement bodies. Fluid inclusion observation shows that in early and main mineralizing stages inclusion types are gas and gas-liquid inclusions, respectively. Gas inclusions occur in isolation in vein quartz, their homog-enization temperature is 372-306°C, and salinity 3.7-1.0 wt% NaCl. Gas-liquid inclusions occur in clusters or healed fractures but do not cut quartz boundary with homogenization temperature 342-267°C and salinity 1.9-0.8 wt% NaCl. Stable isotope measurements show that at main gold mineralization, hydrogen and oxygen isotopic ratios of the mineralizing fluids are -70.8‰-108.4‰ and 2.44‰-4.05‰, respectively. Primary ore fluids in Dongping are higher temperature and lower salinity NaCl-CO2-H2O fluids, and come from Yanshanian granitic magmatism. Fluid im-miscibility, fluid-rock interactions and meteoric water adding were main reasons for gold deposition.展开更多
基金the Key Programs of Chinese Academy of Sciences (Grant No. KZCX1-07) and the Projects from Ministry of Science and Technology of China (Grant No. G1999043207).
文摘The Dongping gold deposit is contained within an inner contacting zone of the Hercynian Shuiquangou alkali syenite. The ores occur as veins or as replacement bodies. Fluid inclusion observation shows that in early and main mineralizing stages inclusion types are gas and gas-liquid inclusions, respectively. Gas inclusions occur in isolation in vein quartz, their homog-enization temperature is 372-306°C, and salinity 3.7-1.0 wt% NaCl. Gas-liquid inclusions occur in clusters or healed fractures but do not cut quartz boundary with homogenization temperature 342-267°C and salinity 1.9-0.8 wt% NaCl. Stable isotope measurements show that at main gold mineralization, hydrogen and oxygen isotopic ratios of the mineralizing fluids are -70.8‰-108.4‰ and 2.44‰-4.05‰, respectively. Primary ore fluids in Dongping are higher temperature and lower salinity NaCl-CO2-H2O fluids, and come from Yanshanian granitic magmatism. Fluid im-miscibility, fluid-rock interactions and meteoric water adding were main reasons for gold deposition.
