STRUCTURAL INVESTIGATION IN SOUTHEAST OF THE BATLAQ-E-GAVKHUNI (CENTRAL IRAN), WITH SPECIAL TO MINERALIZATION OF THE REGION

The study area is situated southeast of Gavkhuni, west of the Yazd province. The main lithological units of the region are Eocene to Miocene volcanic rocks, although Cretaceous limestone and sandstone and Quaternary deposits are also present in the study area. Geographical position, lithological properties and structural trend indicate that this area is situated in the Orumieh-Dokhtar belt, which is an island arc consisting of Eocene to Quaternary rocks. The Dehshir fault is a major tectonic structure with neotectonic activity in the eastern part of the area. Satellite data processing and field observations show that the Dehshir fault and the Khottab fault in the western part of the area make an 18-km wide dextral shear zone with NW-SE trend. In this regard, compressive structures such as folds and thrust faults also trend NW-SE. Riedel and anti-Riedel fractures form angles of 30° and 70°, respectively, with the Dehshir and Khottab faults in SE of Gavkhuni. The study shows that the Sefidkuh-Khaybar tectonic zone is a major Riedel fracture, and several granitic intrusives are present in this zone. Intrusive activity in Eocene period caused Cu, Zn, Au, Ag and Ba mineralizations with associated propylitic, argillic and silication alterations. It is concluded from the study that the Gavkhuni area is a dextral shear zone and within the Riedel fractures there are indications of mineralization. The results of study suggest that the Sefidkuh-Khaybar zone is tectonically fractured and is potentially-mineralized. The mineralization is associated with acidic volcano-sedimentary and intrusive rocks. Based on the geotectonic setting of the area, the suite of host rocks, alteration and mineralographical studies, mineralization in the Sefidkuh-Khaybar area is categorized as massive sulfide.