General exploration studies of Rah Chaman area, Razavi Khorasan province

The Rah Chaman exploration area is in the western region of Razavi Khorasan, specifically Sabzevar town, located 110 km northwest of Sabzevar and north of Rah Chaman village. Geographically, this area lies in the northeast of Iran, between the longitude of 56⁰ 57’ 8/24” to 57⁰ 00’ 4/30” east and the latitude of 36⁰ 50’ 6/1” north. It is part of the Hardeh Joveyn (Joveyn) range, which is a mountainous area north of the Joveyn plain. The stratigraphic units present in the Rah Chaman area closely resemble those found in the eastern Alborz structural zone. These units have formed in an arch-shaped structural bend between the eastern Alborz to the north and the Sabzevar zone to the south. The area contains highly deformed Precambrian and Late Cambrian bedrocks, which have been intruded and cut by post-Eocene intrusive and semi-deep masses. The oldest outcrop units in Rah Chaman consist of dark grey to greenschist and phyllite rocks, as well as altered rhyolite rocks equivalent to the Kahar formation. Younger volcanic rocks dating back to the post-Eocene period are also present, including dacite, dacite-andesite, and Thracian quartz with andesite. During the Oligocene to Miocene periods, semi-deep igneous masses with granitic to diorite composition intruded the older units, leading to widespread copper mineralization in the region. The most significant copper mineralization in the Rah Chaman area is found north of the Kalateh-ye Soleyman farm, attributed to the intrusion of upper Oligocene-lower Miocene micro granodiorites. This mineralization has resulted in the expanded and scattered presence of copper in the exploration area of Rah Chaman.