Trace Element and Sulfur Isotopic Analysis of Pyrite from the Luyuangou Gold Deposit, Xiong’ershan Au-Ag Polymetallic District, Central China: Implications for The Origin and Evolution of Ore-Forming Fluids

The Luyuangou gold deposit is located in the eastern section of Xiong’ershan Au-Ag polymetallic district (XESPMD) and consists a few gold-bearing veins found EW-striking faults Archean Taihua Mesoproterozoic Xiong’er Groups. deposits contain numerous pyrites thin quartz veins, representing an ideal tool for explaining enigmatic genesis XESPMD. distributions trace elements sulfur isotopes pyrite were investigated to define origin evolution ore-forming fluids. Five generations have been identified: coarse-grained euhedral cores (Py1-1) margins (Py1-2) milky fine-grained (Py2) host rocks, (Py3) + sulfide (Py4) calcite veins. indicated that Py2 Py3 represented main minerals contained high concentrations As, Au, Ag, Pb, Zn, Cu, controlled by micro/nanoinclusions. δ34S values five ranged from −19.5 3.4‰. (−15.4 −6.1‰) (−19.5 −12.4‰) had lowest values, indicating originated oxidizing fluid. Py1 showed (−0.3 1.9‰) corresponding magmatic origin. Py4 (1.1–3.4‰) displayed highest rock under action meteoric water cycles. Analyses pyrite’s isotopes, combination with geological evidence, fluids contributed formation deposit. interacted during mineralization period. changing physicochemical conditions mineralized caused precipitation large amount other elements.