北祁连清水沟—白柳沟矿田铜多金属矿床流体包裹体研究

Fluid Inclusions in Quartz from Qingshuigou-Bailiugou Copper-Polymetallic Ore Field,North Qilian Mountains

清水沟—白柳沟矿田是北祁连西段重要的铜多金属矿田之一。采用显微测温和激光拉曼光谱分析技术对该矿田与矿石矿物共生的石英中的流体包裹体进行了研究,结果显示,清水沟—白柳沟矿田的流体包裹体类型主要有纯液相包裹体、气-液两相包裹体和含液体CO2包裹体等3类,气-液两相包裹体液相成分主要以盐水为主,气相成分主要以CO2为主。成矿流体均一温度和盐度变化范围较大,具有中等密度的特征,可能为岩浆热液与海水的混合来源。

The Qingshuigou-Bailiugou ore field, located in the western part of north Qilian Mountains, is one of the important copper-polymetallic ore deposits in China. The authors for the first time studied the fluid inclusions within quartz for the representative ore deposit by using homogenization method and Laser Raman method. The results showed that the fluid includes three types of inclusions： single-phase liquid inclusion, two-phase liquid-vapor inclusion and the CO2-bearing three phase inclusion. The liquid and gas in two-phase liquid-vapor inclusion were rich in H2O and CO2, respectively. The larger range of homogenization temperatures and the salinity with moderate density are the main characteristic of ore-forming fluid. It is suggested that the ore-forming fluid may be derived from the mixed seawater and magmatic water. The above study is of great significance for further researches on the systematic ore deposit geochemistry in this area.