Geochemical Characteristics, Origin, and Evolution of Ore-Forming Fluids of the Khut Copper Skarn Deposit, West of Yazd in Central Iran

摘要: The Khut copper skarn deposit is located at about 50 km northwest of Taft City in Yazd province the middle part Urumieh-Dokhtar magmatic arc. Intrusion granitoid Oligocene–Miocene age into carbonate rocks Triassic Nayband Formation led to formation marble and a calcic skarn. contains high grade Cu mineralization that occurs mainly as open space filling replacement. Cu-rich sulfide samples from mineralized are also anomalous Au, Zn, Pb. In contrast, only weakly W. divided garnet garnet–pyroxene zones. Paragenetic relationships microthermometric data fluid inclusions calcite indicate compositional evolution minerals occurred three main stages follows. (i) early prograde stage, which characterized by Mg-rich hedenbergite (Hd53.7Di42.3–Hd86.1Di9.5) with Al-bearing andradite (69.8–99.5 mol% andradite). temperature varies 400 500°C 500 bar. (ii) late stage manifested almost pure (96.2–98.4 mol% Based on inclusion garnet, salinity this estimated vary 267 361°C 10.1 21.1 wt% NaCl equivalent, respectively. Pyrrhotite precipitation started during stage. (iii) retrograde an exoskarn, consists assemblage ferro-actinolite, quartz, calcite, epidote, chlorite, sphalerite, pyrite, chalcopyrite partially replaces earlier mineral assemblages under hydrostatic conditions fracturing Fluids yielded lower temperatures (T < 260°C) declined ∼8 equivalent. last supergene weathering/alteration represented iron hydroxide, Cu-carbonate, clay minerals, calcite. Sulfur isotope (δ34S +1.4 +5.2‰) show igneous sulfur source. Mineralogy compositions consistent deposition intermediately oxidized slightly fS2 shallow crustal levels compared those other typical Fe-bearing Cu–Au systems.