内蒙古柳坝沟金矿床流体包裹体研究

Fluid inclusion study of Liubagou gold deposit in Inner Mongolia

对柳坝沟金矿床的包裹体进行系统的岩相学、显微测温和激光拉曼光谱研究,结果表明:包裹体的主要类型有富液包裹体、富气包裹体、CO2-H2O和含子矿物多相包裹体。流体包裹体液相成分为水,气相成分主要为CO2及H2O,并含有少量或微量的N2、H2S、CH4等挥发份。成矿流体属中高温、中低盐度、中等密度的NaCl-H2O-CO2体系。矿床形成于中深成矿环境。矿床的成矿作用是一个温度退缩和盐度降低的过程,成矿过程中发生过多次流体沸腾作用,流体的沸腾和CO2流体在Au成矿过程中发挥着重要作用。

Petrographic,Microthermometry and Laser Raman Spectroscopy were used to study fluid inclusions of Liubagou gold deposit in detail.Both Petrographic observations and Microthermometry temperature results indicate that the main types of fluid inclusions are fluid-rich type,gas-rich type,three-phase CO2H2O type and multiphase with daughter mineral-bearing type in four mineralization stages.The ore-forming fluids belong to the medium-high temperature,medium-low salinity,low-density NaClH2OCO2 system and the deposit was formed in the medium-plutonic environment.Raman results indicate that liquid composition of fluid inclusions is H2O,vapor composition of fluid inclusions are mainly CO2 and H2O,the others may contain a small amount of N2,H2S,CH4 and some volatile components.The Ore-forming process of the Liubagou gold deposit was a gradually reduction process of temperature and salinity,during which occurred many actions of fluid boiling.Fluid boiling action and CO2 fluid played an important role in Au mineralization.