Abstract: Kuhai gold-bearing mercury deposit is located in the southern orogenic belt of Eastern Kunlun. Its wall rocks are a suit of shore to shallow sea facies carbonaceous carbonate and quartz sandstone formations. Ore bodies are jointly controlled by both strata and structures, and usually they are distributed in folded layers’ fissures, structural fissures and joints or in the broken belts of fold flanks. Metallogenic fluids are mainly rock formation water and meteoric water as well as possible addition of magmatic hydrothermal solutions. The ore-forming fluids contain NaCl of 1.90%-5.70% and the density is in the range of 0.78-0.97 g/cm³. The fluid inclusions show homogenized temperature at 118.8-291.6℃. The metallogenic pressure is about 43.24 MPa, correspondent to a depth of 4.56 km. Studies indicate that the Low Permian carbon-bearing strata in the area has provided the main ore-forming materials which were further mobilized by magmatic hydrothermal fluids during the Late Triassic tectonic activities and finally formed as mineral deposit at the broken folded belts. Overall, Kuhai mercury deposit is a middle to low temperature hydrothermal mineral deposit and is considered as an epizonal deposit in terms of orogenic gold deposit series.

Key words: Kuhai mercury（gold） deposit, geological characteristics, orogenic gold deposit, Qinghai Province