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چکیده
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The Muteh gold deposit (NE of Golpaygan) composed of NW-SE trending gold-quartz veins hosted in a metamorphic complex, located in the central part of Sanandaj-Sirjan intrusive-metamorphic belt. Gold mineralization is associated with quartz veins that formed during regional deformation across the mylonitic zones in the metamorphic rocks of predominantly meta-volcanic, gneiss and schist. Sulfidation (pyritization) and silicification are the dominant hydrothermal alteration adjacent to ore body. The quartz-sulfide veins with sulfide content of 10 to 60% are dominated by pyrite, chalcopyrite, emplectite, arsenopyrite and minor galena and sphalerite. Native gold in the veins occurs as inclusions in pyrite and chalcopyrite and as fracture fillings within pyrite crystals. The second generation of pyrite (PyII) shows a range of 0.03 to 0.31 wt.% Au and 0.00 to 0.26 wt.% of As, while contemporaneous chalcopyrite shows up to 0.30 wt.% of Au, up to 0.12 wt.% As, and up to 0.15 wt.% Hg in their chemical composition. Three types of fluid inclusions (FI) are associated with auriferous quartz-sulfide veins include; CO2-rich or carbonic FI with average Th of 19.9°C, aqueous-carbonic FI (average salinity of 7.4 wt.% NaCl eq. and Th of 297.7°C) and aqueous FI (average salinity of 8.65 wt.% NaCl eq. and Th of 254.9°C). Documented evidences such as metaluminous and subalkalic granitoid intrusive rocks, occurrences of albite and/or K-feldspar with orebodies, reduced metal distributions of Au-Bi±Te±As accompanied with carbonic hydrothermal fluids, shows that gold mineralization in the Muteh deposit resemble the intrusion-related gold systems.
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