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Abstract
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The Kuh-e Dom gold prospect in central Iran is located in the Urumieh-Dokhtar Magmatic Belt, and is characterized by copper–iron oxide and gold veins, stockworks and breccias hosted by the Eocene Kuh-e Dom intrusion. Mineralization is located within NE–SW to WNW–ESE sinistral faults and likely formed in a subduction-related continental margin. The deposits have a distinct metal composition of Fe, Cu, Bi, Co, and Mo with gold (up to 3 g/t), and the mineral assemblages are quartz, hematite, pyrite, chalcopyrite, emplectite, magnetite, native gold, calcite, barite, chlorite, and tourmaline. Three paragenetic stages of mineralized quartz veins are distinguished in the Kuh-e Dom prospect, including: (i) hematite-bearing quartz veins, (ii) quartz-sulfide stockwork and breccia veins, and (iii) quartz-calcite±sulfide infilling veins. Sodic (albitization), potassic, and quartz-calcite±chlorite pervasive alterations are commonly associated with these three mineralization stages. Three types of fluid inclusions have been identified at Kuh-e Dom, including: aqueous two-phase (H2O−NaCl−CaCl2±FeCl2), halite-saturated aqueous (H2O−NaCl±KCl), CO2-bearing (H2O–CO2±CH4 and CO2±CH4) fluid inclusions. Fluid inclusions data indicate that a hypersaline (~35 wt.% NaCl equiv.), aqueous magmatic-derived hydrothermal fluid was trapped at about 400°C and a pressure of nearly 4 kbar, forming early hematite-bearing quartz vein. These high salinity fluids were progressively diluted with decreasing quantities of magmatic water further away from Kuh-e Dom intrusion, suggesting substantial input and fluid mixing of meteoric water during the middle and late stages of mineralization.
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