Chemical Fingerprinting Characteristics of Pyrite from the Lianhuashan Gold Deposit, Chifeng, Inner Mongolia, and Their Significance in Ore Deposit Geology

The Lianhuashan gold deposit is situated on the northwestern margin of the Chifeng-Chaoyang Gold Metallogenic Belt. Due to prolonged mining, the remaining gold reserves are insufficient to sustain continuous production, necessitating enhanced exploration in deep and peripheral zones. This study investigates metallogenic mechanisms and deposit types by analyzing pyrite compositional typomorphism and proposes recommendations to guide prospecting. The results show that the Co/Ni elemental ratios and the As-Co-Ni ternary diagram of pyrite indicate that pyrite genesis in the Lianhuashan gold deposit is relatively complex, constrained by multiple factors, including the Jianping Group, regional metamorphism, and magmatic hydrothermal activity. The characteristic Au/Ag and S/Se ratios in pyrite indicate magmatic hydrothermal signatures, suggesting that ore-forming fluids formed primarily through magmatic activity in the mining area. The w(Fe)/w(S+As) ratio, comprehensive pyrite trace element ratio H, and trace element assemblage distribution diagram reveal favorable prospecting potential at greater depths. Combined with ore-controlling structural analysis, we infer that a high-grade orebody may exist within a 200-meter downward extension of Vein No. 51.