Mineralogy, ore chemistry, and fluid inclusion studies in Gushfil Pb-Zn deposit, Irankuh mining district, SW Isfahan

Gushfil deposit is located SW Isfahan within Malayer-Isfahan Metallogenic Zone. Mineralization occurs at contact of Jurassic shale and Cretaceous dolomite as epigenetic with structural control. Paragenetic minerals are sphalerite, galena, and pyrite associated with dolomite, quartz, organic matter, and minor barite as gangue minerals. These minerals show berrecia, veinlets, open space filling, and dessiminated textures. Dolomitization and silicification are the most important alteration zones. Ore chemistry indicates galena is Ag and Sb-rich and Bi-poor. Sb/Bi ratio in galena is up to 14, which is indicator of low temperature deposits. Sphalerites are Fe and Cd-rich type. Based on fluid inclusion studies, formation temperature of Gushfil deposit is 223 to 302oC. It is formed by NaCl and CaCl2-bearing fluid with 9.5 to 16.7 wt. % salinity. Host rock type, stratabound and epigenetic mineralization, postsedimentary fault controlling, texture, ore types and gangue minerals, and no associated with igneous activity indicate Gushfil deposit is similar to MVT deposits, but ore-fluid temperature is higher than typical mineralization in the world.