Compositional Variations of Sphalerites and Their Genetic Characteristics from Gold and/or Silver Deposits in Central Korea

한국 중부지역 금은광상산 섬아연석의 조성변화와 성인적 특성

Chemical compositions of sphalerites from 25 gold and/or silver deposits in central Korea were obtained with an electron probe microanalyzer. The FeS contents of sphalerites depend generally upon the assemblage of associated iron sulphides (pyrite and/or pyrrhotite) especially. The sphalerites coexisting with pyrrhotite show a narrow range of FeS variation, but the sphalerites associated with pyrite and/or pyrrhotite have the variable and wide range of FeS contents. The sphalerites from Au-dominant deposits, which vary considerably in each deposit, are generally characterized by high CdS content and low MnS content. On the contrary, the sphalerites from Ag-dominant and Au-Ag deposits tend to be characterized by relatively high MnS and very low CdS content. Based upon the mineralogy, fluid inclusions and stable isotope data, the Au-dominant deposits were formed under higher temperature and deeper depth than the Ag-dominant and Au-Ag deposits. The results suggest the possibility that the diverse sources and evolution of ore fluid at the time of ore deposition are responsible for the deposition of Cd and Mn components in sphalerites.