Effect of S on the aqueous and gaseous transport of Cu in porphyry and epithermal systems: Constraints from in situ XAS measurements up to 600 °C and 300 bars

Overall, these results suggest that the presence of S of mixed oxidation state (sulfide S2 −, sulfite S4 + and sulfate S6 +) limits transport of Cu in porphyry and epithermal systems and may even trigger Cu precipitation. Furthermore, these experiments provide evidence that the presence of the S3− ion does not increase Cu solubility in fluids. Thus, if present in such environments, S3− ion could fractionate Cu from Au in porphyry-epithermal environments.