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四川乌斯河铅锌矿床是赋存于震旦系灯影组白云岩中的大型铅锌矿床.本次研究结合最新的野外地质现象发现该矿床除存在前人所强调的沉积成矿作用以外,热液成矿作用非常明显.对该矿床流体包裹体进行细致的岩相学、显微测温和激光拉曼研究,揭示成矿流体特征,并探讨成矿机制.研究结果显示该矿床包裹体类型较为单一,以气液两相为主,均一温度主要集中于120~260℃,平均盐度为10.0%NaCl eqv,压力为32~68MPa,成矿流体为中-低温、中等盐度.激光拉曼测试显示包裹体气相成分含有CH_4、H_2S、C_2H_6、C_2H_2、N_2和NH_3,为多元共存的流体体系.在热驱动力下(120~260℃),流体混合作用提供了物质基础(SO_4~(2-))、催化剂(Mg~(2+))和还原剂(有机质、CH_4和H_2S)促使硫酸盐热化学还原反应(TSR)启动.TSR反应过程中流体pH发生变化,进一步促进了金属硫化物沉淀.
The Uzhe lead-zinc deposit in Sichuan Province is a large-scale lead-zinc deposit hosted in the Sinian Dengying Formation dolomite.This study combined with the latest field geology shows that in addition to the previous emphasis on sedimentary mineralization, The mineralization of hydrothermal fluids is very obvious.The fluid inclusions in this deposit are meticulously studied by petrography, microscopic temperature measurement and laser Raman, revealing the characteristics of ore-forming fluid and discussing the metallogenic mechanism.The results show that the fluid inclusions The types are single, mainly gas-liquid two phases, the homogenization temperature is mainly concentrated in the range of 120-260 ℃, the average salinity is 10.0% NaCl eqv, the pressure is 32-68 MPa, and the ore-forming fluids are medium-low temperature and moderate salinity. The Raman test shows that the gas phase composition of the inclusions contains CH_4, H_2S, C_2H_6, C_2H_2, N_2 and NH_3, and is a coexistent fluid system with multiple coexistence.The fluid mixing provides the material basis (SO 4 ~ (2-)), catalyst (Mg 2+) and reductants (organic matter, CH 4 and H 2 S) promote the start of thermochemical sulfate reaction (TSR), which changes the pH of the fluid during the TSR reaction, Sulfide precipitation.