Geochemistry of sulfide minerals from skarn Cu (Au) deposits in the Fenghuangshan ore field, Tongling, eastern China: Insights into ore-forming process

•Baoshantao and Fenghuangshan deposits are typical skarn-type ore deposit.•Gold, Ag, Sb, Pb and Bi are mainly of lattice bound appearance in pyrite and chalcopyrite.•Skarn Cu (Au) mineralization was formed in a high-temperature, high oxidized magmatic-hydrothermal fluid.•A sedimentary component from subducted slab contributed to the skarn Cu (Au) mineralization.