江西大吉山钨矿床流体包裹体研究

Fluid inclusion study on the Dajishan tungsten deposit in Jiangxi Province

文章采用流体包裹体组合的方法,在详细的岩相学研究的基础上,对大吉山钨矿床含矿石英脉中的流体包裹体进行了显微测温、拉曼探针和同位素的分析。结果表明,大吉山钨矿床具有明显的两期流体活动特征,流体组分主要为水及CO2,并含有少量的CH4、N2。成矿流体的主要来源为岩浆水,后期受到雨水影响。根据CO2的三相包裹体(Ⅱ型包裹体)测温数据计算得出成矿流体的捕获压力为75.6～93.1MPa,按静岩压力换算成成矿深度最小为2.91～3.58km。

The Dajishan tungsten deposit is a well - known large - sized quartz - vein type tungsten - polymetallic deposit in southern Jiangxi Province. Based on detailed petrographic observations, the authors carried out micro - thermometric, Raman micro-scope probe and isotope analysis studies of fluid inclusions by applying means of Fluid Inclusion Assemblage （ FIA ） in the Dajishan tungsten deposit. The study result indicates that the Dajishan tungsten mineralization process experienced two stages of fluid activities, and the mineralization fluid is characterized with main components of H2O and CO2 and minor CH4 ,N2. The hydrogen and oxygen iso-topic study shows that the ore - bearing fluid is mainly derived from magmatic water, and infiltrated by the atmospheric water in the late stage. According to the homogeneous temperatures of three-phases CO2 fluid inclusions （ Ⅱ -type inclusion） ,the ore-forming pres-sure is about 75.6-93.1 MPa by calculation,and the ore-forming depth is about 2.91-3.58 km in the case of the lithostatic pres-sure