Gold Metallogeny in the East of Iran

Abstract

Exploration in the east of Iran (EI) led to the identification of four types of gold mineralization in nine regions, consisting IOCG-type gold deposits (Qaleh-Zari, Koodakan, and Kuh-e-Zar), epithermal-type (Arghash, Khunik, and Chah Shaljami), reduced intrusion-related gold system (RIRGS) types (Tarik Darreh and Hired), and mesozonal-type orogenic gold deposits (Torghabeh). The compositional diversity of porphyry intrusions in these tectono-magmatic environments generally form in volcanic arc settings except for Hired deposit that is in a syn-collision setting, with the most restricted range (different types of granitoids that are partly high-K calk-alkaline to shoshonitic) which occurred in three main episodes. They are: (1) Triassic in which Tarik-Darreh and Torghabeh deposits generated, (2) Eocene –Oligocene episode, when the Qaleh-Zari, Koodakan and Kuh-Zar, Khunik and Chah-Shaljami formed, and (3) Oligo-Miocene episode for Hired deposit. The reduced intrusion-related gold (RIRGS) system (Hired and Tarik Darreh deposits) are related to the reduced ilmenite-series granitoid, whereas the other deposits are related to oxidized magnetite-series granitoids. Evaluation of tectonic setting as well as local controls strongly suggests that continued exploration in the region will lead to the identification of additional gold deposits.