Helium and argon isotope systematics in fluid inclusion of the gold deposits along the Daduhe River, Sichuan Province, West China

摘要

Helium and argon isotopic composition of fluid inclusions released by crushing pyrites are reported from the gold deposits along Daduhe River, Sichuan Province, China. The gold deposits are hosted in Precambriam basement of Kangding complex. 3He/4He ratios of fluid inclusions in pyrite range from 0.16 to 0.86 Ra, whereas 40Ar/36Ar range from 332 to 3288. Analyses of He, Ar isotope from three gold deposits demonstrate the paleofluids were a mixture between low temperature metamorphic water and meteoric water. Compared to crustal helium, the higher helium Ra was the result of hydrothermal leaching from Kangding basement complex. From south to north in the Daduhe ore district, more and more meteoric water was involved in ore-forming fluid system.