摘要
新安子钨锡矿床主矿脉中流体包裹体显微测温学研究表明石英中流体包裹体的均一温度集中在320～360℃、260～300℃和180～230℃3个区间,代表成矿的3个阶段,黑钨矿主要形成于高温阶段,硫化物则主要形成于中温阶段;岩浆热液和大气降水热液的混合及其伴生的沸腾作用发生于成矿的晚期阶段(180～230℃),因此它们可能不是W、Sn和硫化物成矿的主要机制.激光拉曼光谱分析表明石英和黄玉中的流体包裹体气相成分以H2O为主,含少量CH4和CO2,并呈现出随均一温度的降低,CO2的含量降低,CH4含量升高的变化趋势;这一变化趋势表明流体由氧化性逐渐向还原性转变,这可能是造成硫化物成矿的主要机制.
Fluid inclusions sampled from mother lodes of Xin’anzi quartz type W-Sn deposit were examined by petrography, microthermometry and Raman microprobe. The results show that：①the homogeneous temperatures of fluid inclusions in the quartz distribute intensively in three intervals, i.e. 320 ℃~360℃, 260 ℃~300 ℃ and 180 ℃~230 ℃, which might correspond to the three stages of the whole ore-forming process. Wolframite is formed mainly in the high-temperature stage while sulfides in the medium-temperature stage; ② The process that mixing of magmatic water with meteoric water and its companion boiling are probably not the key mechanism of W-Sn and sulfides mineralization because they have occurred in the late stage of mineralization （180 ℃~230 ℃）; ③The gaseous phase of the fluid inclusions both in quartz and in topaz are composed of H 2O and a small amount of CO2 and CH4. With the decrease of the homogeneous temperatures, the content of CO 2 tends to degrade while that of CH4 is the opposite. It indicates that the fluid transformed gradually from an oxidizing solution to a reducing one, which might be the main mechanism which lead to the sulfide mineralization.
出处
《有色金属科学与工程》
CAS
2013年第5期70-78,共9页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金资助项目(41063001)
矿床地球化学国家重点实验室开放基金资助项目(201004)
关键词
新安子
钨锡矿床
流体包裹体
成矿机制
Xin’anzi
W-Sn deposit
fluid inclusion
sulfide mineralization
