Study of involved fluids and geochemistry of rare earth elements of Aghbolagh copper deposit, in North Oshnavieh, West Azerbaijan Province of Iran

Aghbolagh copper deposit is located in the southwest of West Azarbaijan Province, 10 km north of Oshnavieh city. Most of the existing rock outcrops in the area include Cambrian deposits (carbonated and clastic deposits). These deposits are metamorphosed by intrusive-granite masses (skarn-genesis). The infiltration of the mineralization solution at distances beyond contact and inside the sandstone sequences has resulted in the formation of copper ore veins. For microscopic and geochemical studies, 21 thin sections, and 22 doubly-polished cross-sections, 22 XRD specimens, 22 ICP-MS specimens, and three samples for analysis of 10 oxides were analyzed by Zarazma Corporation. In the study of the fluids involved, measurements were made using a Linkham THMSG600 heater and freezer plate, mounted on a polarized microscope with a separate stage and Olympus model. Studies on quartz minerals (3 samples) and garnet minerals (2 samples) were performed on five polished double sections by micro-thermometry measurements on 30 inclusion in quartz mineral and 15 inclusion in garnet mineral at Rizkavan Land Company. The results show that the La/Y ratio, which is a proper indicator for the pH conditions of the formation environment of ore deposit, in Aghbolagh deposit is a range from 0.09 to 2.26. The granite mass has the highest amount, and the skarn zone represents two types of conditions. Type 1: Section where the La/Y> 1 ratio observed in samples close to the skarn mass and ore. Type 2: Part where the ratio La/Y <1 is close to marble lithology. In the case of a vein deposit, the samples have mineralization under alkaline conditions, and other samples show acidic conditions. The examination of fluid inclusions determined two main groups of fluids in this mineralization system. Group 1: Supersaturated fluids of salt, which is the origin of halite multiphase inclusions in the garnet ore during the progressive skarn alteration process. Group 2: Salt-saturated fluids, which are the source of fluid-rich two-phase intermediates in the garnet and quartz minerals, and have been effective in regressive alteration in the skarn system.