Sulfide Minerals and Fluid Chemistry of Zn–Pb Deposits in Central Sanandaj–Sirjan Zone, Iran

A wide variety of Zn–Pb deposits have been reported along the Malayer–Esfahan metallogenic belt in Iran. This metallogenic belt is localized in the central part of the Sanandaj–Sirjan zone. In the present study, sphalerite and galena chemistry of four Zn–Pb deposits (i.e., Gol-e-Zard, Baba-Gholleh, Tekyeh and Emarat deposits) are examined in this area. Also, fluid inclusion studies from four deposits were examined to study possible relationships between trace element chemistry of sphalerite and galena with ore-bearing fluid. The homogenization temperatures increase on average from 94.89 °C (the Tekyeh deposit), 116.83 °C (for the Emarat) to 166.14 °C (Baba-Gholleh deposit) and 181 °C (the Gol-e-Zard). The salinity increases on average from 8.68 wt.% NaCl equivalent (the Tekyeh), 9.33 wt.% NaCl equivalent (the Emarat), to 11.19 wt.% NaCl equivalent ( the Gol-e-Zard) and 12.1 wt.% NaCl equivalent (the Baba-Gholleh). Samples from the Tekyeh and Emarat are typically enriched in Fe, Cu, Cd, Ga, and Ge, while these elements less abundant in the Gol-e-Zard and Baba-Gholleh deposits with Zn/Ag, Zn/Fe, Zn/Cu, Ga/In and Sn/In ratios in sphalerites of two types of Zn–Pb deposits are different. The Tekyeh and Emarat galena are strongly enriched in Ag, Cd and Ge. Based on geological evidence and host rocks, fluid inclusion studies are compared between trace elements in sphalerite with some Zn–Pb deposits. We conclude that Gol-e-Zard and Baba-Gholleh deposits are of sedimentary exhalative type, whereas Emarat and Tekyeh deposits are classified as Mississippi valley type.