江西相山矿田多金属成矿流体特征与成矿作用

Characteristics of polymetallic ore-forming fluid and metallogenesis of the Xiangshan orefield in Jiangxi

随着相山铀矿矿田勘探深度的增加和铀矿科学深钻的实施，在矿田内揭露了大量多金属矿化，流体包裹体和地球化学研究表明，铅锌矿成矿期温度集中在230~300℃之间，成矿压力为12~51MPa，盐度4%~8%NaCleqv，包裹体气体成分主要为CO2，其次为CH4、N2等，矿物组合为铅锌矿＋黄铁矿；黄铜矿成矿期温度集中在320~380℃之间，成矿压力为33~95MPa，盐度8%~12%NaCleqv，包裹体气体主要成分为CO2，其次为CH4、N2等，矿物组合为黄铜矿＋磁黄铁矿＋毒砂，成矿流体具有中高温、高压、中高盐度、还原性、低氧逸度、富CO2的特征，铀和多金属成矿流体均具有深源特征，但铀和多金属成矿作用在时间、空间、蚀变和流体特征上存在明显的差异性，不属于同一成矿作用的产物，为华南早中白垩世成矿阶段不同时期的产物。

Fluid inclusions of polymetallic mineralization in the Xiangshan uranium orefield were studied for the first time in this pa-per. A large number of polymetallic mineralizations were discovered recently with the deepening of geological exploration in the Xiangshan uranium orefield and the implementation of uranium scientific deep drilling. Based on studying petrography, microther-mometry, pressure of ore-forming processes, composition and metallogenic depth of fluid inclusions as well as sulfur, carbon, oxygen isotopic composition, the authors hold that the lead and zinc ore-forming temperatures are mainly concentrated on 230~300℃, the metallogenic pressures are concentrated on 12~51MPa, and the salinities are concentrated on 4%~12%NaCleqv. The fluid inclusions are enriched in CO2 and to a lesser extent in CH4 and N2. The mineral assemblage is mainly sphalerite＋gelenite＋pyrite. The cop-per ore-forming temperatures are mainly concentrated on 320~380℃,metallogenic pressures on 33~95MPa , and salinities on 4%~12%NaCleqv. The fluid inclusions are enriched in CO2 and to a lesser extent in CH4 and N2. The mineral assemblage is mainly chal-copyrite＋pyrrhotite＋arsenikstein. All these data indicate that ore-forming fluids were characterized by medium-high temperature, high pressure, medium-high salinity, low oxygen fugacity and high content of CO 2. The lead, zinc, copper and uranium ore-form-ing fluids were characterized by deep source, but there were obvious different in stage, space, alteration and fluid inclusion characteris-tics of lead, zinc, copper and uranium mineralization, so they were formed in different ore-forming stages and occurred in different separate hydrothermal mineralization processes in early-middle Cretaceous in South China.