Study of metallogenic fluid geochemistry of Sidaogou gold mine.

Sidaogou gold mine is located in the west side of Yalujiang river fault and hosted in the metamorphic rock series of the Gaixian Formation of the Liao he Group. Its ore-forming fluids are enriched in Na+, Ca2+ and Cl- ions and reducing gases (CO, N-2, CH4 and H-2). The values of metallogenic temperat ures and pressures are 160 similar to 280 degreesC and 45 similar to 55MPa, respectively. The values of pH, Eh, fo(2), delta O-18 and deltaD show that the ore-forming environment and fluids are near neutral and weak reducing mixed fluids, respectively.