Geochemistry of main types of gold deposits in shear zones, China

Shear zone-hosted gold deposits in China can be divided into four types: ductile, brittle-ductile, ductile-brittle and brittle, of which the ductile and brittle types are the basic ones. All these types of gold deposits have their own geochemical characteristics. The Hetai gold deposit in Guangdong Province, for example, is a mylonite-type gold deposit in a ductile shear zone. With increasing mylonitization, obvious changes took place in trace elements in minerals and rocks, enriching gold and mineralizing elements. The S and Pb isotope data indicated that the ore-forming materials were derived from the strata. Hydrogen and oxygen isotopic and fluid inclusion studies also implied that the ore-forming fluid was much closer to meteoric water from the early to the late ore-forming stage. The Linglong gold deposit, Shangdong Province, is a quartz-type gold deposit in a brittle shear zone. Changes in rocks, minerals and trace elements occurred in the process of formation of gold quartz veins, and the analytical results of S, Pb, H and O isotopes showed that ore deposition is connected not only with the Jiaodong Group, but also with anatexic granites. This research project was financially supported by the National Natural Science Foundation of China (Nos. 49573189, 49403043) and the Key Gold Project of Chinese Academy of Sciences.