Geothermometric and isotopic studies of Kohroyeh Pb ore deposit (SW Shahreza)

The Kohroyeh Pb-Zn ore deposit is located about 25 Km SW of Shahreza. The ore deposit belongs to Esfahan-Malayer metallongenic belt. Mineralization occurred as veins and veinlets consisting of galena and slight amount of sphalerite, calcite and quartz gangue lying between Jurassic formation (containing shale, siltstone and sandstone) and Cretaceous limestones. The geochemical maps define anomaly, the site of mineralization and concentration of Pb and Zn elements in this area. The C, O and S isotopic studies on calcite and galena show a non-marine and non-sedimentary provenance, and influence of meteoric waters in the genesis of ore deposit as well. On the base of field observations, there is a close relationship between ore bearing veins and faults, tectonic processes and deformation. According to geometric situation of deformed twins of large calcite crystals, the formation temperature of veins and ore deposit is estimated over 250°C. The overall data indicate that the provenance of the Kohroyeh Pb and Zn ore deposit may be considered as epigenetic and categorized as Mississippi valley type similar to Pb and Zn deposit of the SE Missouri.