Early sulfide saturation in arc volcanic rocks of southeast China: Implications for the formation of co-magmatic porphyry–epithermal Cu–Au deposits

It is widely considered that arc magmas are highly oxidized, and can thus dissolve a large amount of sulfur, thereby preventing significant sulfide saturation prior to fluid saturation. Therefore, chalcophile metals (e.g., Cu and Au) are retained in the magma and finally extracted by exsolved hydrothermal fluids. To test this hypothesis, we analyzed the abundances of platinum-group elements (PGEs) in a suite of arc volcanic rocks, which are the...