Abstract:

 The Xinping gold deposit is located in the Liucen ore field in Dayaoshan polymetallic mineralization belt. The ore bodies, hosted in the sandstone and mudstone of Cambrian Huangdongkou Formation, are related to the Xinping complicated anticline and fracture zone of EW-trending faults.Fluid inclusions in quartz suggest that ore-forming fluids are moderate temperature, low salinity, low density and contain CO₂. The cations in fluids are Na⁺, Ca²⁺, Mg²⁺ and K⁺, while main anion is Cl^-. The data of hydrogen and oxygen isotopes indicate that the ore-forming fluids are probably derived from magmatic fluids, and superimposed by metamorphic fluids and meteoric water also involved. The sulfur isotope values in sulfides are narrowly ranged negative not far from zero,which infers that sulfur in ore is a mixture of sulfur from deep source and strata. Our study combined with previous research show that Au has multisources, it mainly sourced from Cambrian strata, but the deep magmatic rocks in the region may also provide some Au. Based on above study, we conclude that the Xinping gold deposit was superimposed mineralization of metamorphism and magmatic-hydrothermal fluids.

Key words: stable isotope, fluid inclusion, ore-forming fluid, Xinping gold deposit, Pingnan County, Guangxi