Helium isotope compositions of Machangqing copper deposit in western Yunnan, China

Helium isotopic composition of inclusion fluid in pyrites from Machangqing copper deposit, China, has been measured. The measurements, with³He/⁴He ratios ranging from 0.46–2.08 Ra, indicate that the helium in ore-forming fluid is a mixture of crust and mantle, and are consistent with the fact that the parental magma responsible for the formation of ore-forming fluid of the deposit is of crust-mantle provenance.