Department of Geology, University of Bu Ali Sina, Hamedan, Iran

The Arzanfood area is located in southeast of Hamadan city, east of the Alvand granitoid. Based on of Iran geological structure zone, it is located in the Sanandaj - Sirjan zone. Quartz veins occur in the metamorphic rocks, including garnet-mica schist and phyllite, and are related to tectonic activity. The most of fault trends complied with N28W-N62W Zagros zone. In the field, three different types of quartz veins have been identified in the region including: 1) veins with a width of less than 10 cm and a length of several meters within the slate and hornfels rocks, 2) veins with a width of less than 2 meters and a length of less than 20 meters with the host rocks are garnet, micaschists and slate, and 3) veins and lenses with a width of more than 2 meters and a length of more than 20 meters that are present in micaschists rocks. Studies of fluid inclusions in quartz mineral show a homogenization temperature from 98 to 408 ° C and salinity ranges from 3.72 to 22.91 wt. % NaCl. Boiling and dilution with surface water are two processes that have been involved in mineralization. Finally, it can be concluded that quartz indices in the region are the product of hydrothermal activity related to metamorphic processes and quartz was deposited from mineralizing fluids in the empty spaces as a result of temperature and pressure reduction.