Hydrothermal calcites from the mississippi valley-type Elmwood-Gordonsville zinc deposits, central Tennessee, U.S.A.; fluid inclusion and stable isotope data

A combination of fluid inclusion characteristics and isotopic compositions of the three stages of calcite in the ore-gangue assemblages of the Elmwood-Gordonsville deposits suggests that the Mississippi Valley-type of mineralization involved two different types of hydrothermal fluids. The earlier phase of mineralization was from relatively high-T and high-salinity formation waters that had experienced extensive interactions with carbonate rocks. Mixing with deep-circulating meteoric water resulted in somewhat cooler but significantly less saline fluids for the later phase of mineralization.