Petrological and geochemical study of trace and rare earth elements in the Miardan Gold mineralization, Bostanabad, East Azarbaidjan Province

The Miardan gold deposit is located near the Miardan village, 15 km west of the Bostan Abad town in the East Azarbaidjan Province. The main rock units in the area include andesitic tuffs and lavas of Eocene age, which host vein-type gold mineralization. The orebody is formed within the altered, crushed and sheared andesitic rocks, in contact with porphyry diorite stock. These rocks have been subjected to siliceous and sericitic alteration by hydrothermal fluids and converted to quartzite and hornfels under the metasomatism related to the intrusive body. Gold mineralization within these rocks occurs as almost vertical sulfide-bearing silicic zones and quartz veins with N300W to N320W trend. Chondrite and primitive mantle-normalized spider diagrams of trace and rare earth elements indicate differentiation of LREE from HREE and enrichment of LREEs. Geochemical indices, such as TiO2 and (Ce+Y+La)-(Ba + Sr), show that supergene fluid played the most important role in the development of alteration zones and mineralization in this area.