Geological, fluid inclusion and isotopic characteristics of the Gardaneshir Zn–Pb deposit, Central Iran

Gardaneshir Pb–Zn deposit is hosted by dolomitic carbonates which is located in the SW Ardestan, central Iran. Ore body is stratabound type in this deposit. Primary ores in this type are composed of sphalerite, galena, barite and quartz with massive, banded, veined and disseminated structures. Evaluation of ore-grade at the Gardaneshir Pb-Zn deposit, based on chemical analysis which indicates average of 4.35% Pb, 0.17% Zn, 20 ppm Ag in form of galena, sphalerite, minor cerussite and smithsonite occurred along brecciated and silicified fractures. Based on studies in gangue minerals, liquid-rich two phase (L+V) inclusions as predominant types were recognized. These types of inclusions are homogenized into liquid state with ranges of TH and related salinities as 78-183 NaCl wt% and 216-283 C, respectively. These microthermometric data reflect the nature of two populations of fluid inclusions originating from different source. Furthermore; the range δ34S from -0.6 ‰ to -20.4‰ that have been extracted by galena can be an evidence of bacterial sulfate reduction in a subsidence sedimentary basin. This study suggests that the Gardeneshir Pb–Zn deposit is an epigenetic, thrust fold-controlled and stratabound deposit with fluids and metals derived via the Triassic sedimentary strata.