Fluid inclusion and H-O-S-Pb isotope systematics of the Chayong Cu-polymetallic deposit, Sanjiang Metallogenic Belt, Qinghai Province, China

The Chayong Cu-polymetallic deposit is a recently discovered Cu-polymetallic deposit hosted in the Sanjiang Metallogenic Belt within the Tibetan Plateau of China to the northeast of the North Qiangtang terrane. The ore body occurs in siltstone and is controlled by a northwest-trending fault structure. According to the associations, assemblages, and cutting relationships between ore veins, the hydrothermal mineralization period can be divided into three mineralization stages: (1) a molybdenite mineralization stage, (2) a Cu-polymetallic sulfide stage, and (3) a quartz-carbonate stage. Two types of fluid inclusions (FIs), namely, liquid and vapor-rich inclusions, are present in quartz associated with sulfide minerals. Early-stage FIs are both liquid and vapor-rich, homogenized at temperatures ranging from 364.1 to 384.2 °C, and have salinities ranging from 0.70