(1. 中南大学 地球科学与信息物理学院 有色金属成矿预测与地质环境监测教育部重点实验室，长沙 410083;
2. 中南大学 地球科学与信息物理学院 有色资源与地质灾害探查湖南省重点实验室，长沙 410083)
摘 要: 采用“流体包裹体组合(FIA)”的研究方法，对矿田主成矿期早、中、晚阶段的流体包裹体进行显微测温和拉曼探针的分析。结果表明:早阶段流体包裹体主要为水溶液包裹体和CO2三相包裹体，中阶段主要为富液相水溶液包裹体和CO2两相包裹体，晚阶段主要发育水溶液包裹体。从早阶段到晚阶段，流体包裹体的均一温度逐渐降低，盐度先升高再降低。3个阶段中水溶液包裹体的组分主要为水，除CO2外，还检测到少量H2S、CH4和N2。早阶段成矿流体在演化过程中发生以CO2逸失为特征的流体不混溶作用，是该阶段含矿流体中络合物分解并沉淀成矿的主要因素;中阶段成矿元素沉淀的主导因素则是流体的混合作用;而晚阶段成矿元素沉淀的主导因素推测为流体体系的自然冷却。
关键字: 成矿流体;石英脉型;钨矿床;锡田
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and
Geological Environment Monitoring, Ministry of Education,
School of Geosciences and Info-Physics Central South University, Changsha 410083, China;
2. Key Laboratory of Non-ferrous Resources and Geological Hazard Detection,
School of Geosciences and Info-Physics Central South University, Changsha 410083, China）
Abstract:According to cross-cutting relations and minerals assemblages, three stages were cataloged in the vein type deposits:early quartz-(molybdenite)-wolframite veins, middle quartz-(wolframite)-sulfide veins and late quartz-pyrite- fluorite veins. Based on detail petrography of fluid inclusion assemblage (FIA), fluid inclusions of three stages were studied by microthermometric and Raman microspectroscopic analysis. Mainly aqueous and CO2-H2O three-phase inclusions in quartz-(molybdenite)-wolframite veins, liquid-rich aqueous and CO2 two-phase inclusions in quartz-(wolframite)-sulfide veins and only aqueous inclusions in quartz-pyrite-fluorite veins were found. The results show that the homogenization temperature of the fluid inclusions decreases from early veins to late veins, while the salinities of fluid inclusions increase in middle veins and decrease in late veins. According to Raman microspectroscopic results, the fluid inclusions of three stages is mainly H2O, moreover, minor CO2, rare H2S, CH4 and N2. The metals precipitation are fluid immiscibility caused by CO2 escaping in early stage, fluid mixing in middle stage and natural cooling of fluid system in late stage.
Key words: ore-forming fluid; quartz-vein type; tungsten deposit; Xitian
