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赣北石门寺钨矿是近几年来发现的超大型钨多金属矿床,该矿床很有可能打破传统江西“南钨北铜”的资源格局。为揭示成矿流体特征及探讨流体演化过程,研究选取石门寺钨矿床石英大脉型矿体含矿石英中的流体包裹体进行岩相学、显微测温学以及激光拉曼光谱分析等测试。岩相学观察发现,石门寺钨矿床以富液相包裹体为主,另发育有富气相、含CO_2三相、纯液相及纯气相包裹体。显微测温结果显示,均一温度分布在147.1℃~316.2℃之间,主要集中在201.5℃~259.2℃,均值为211.1℃;盐度w(NaCl_(eq))分布在0.88%~7.31%之间,集中在1.05%~3.06%,均值为2.45%;密度分布在0.79g/cm3~0.94g/cm~3之间,集中在0.82g/cm~3~0.92g/cm~3,均值为0.87g/cm~3。拉曼分析除检测到CH_4外,还不同程度的检测到CO_2,N_2的存在。表明成矿流体性质为中温、低盐度、低密度的NaCl-H_2O-CH_4±(CO_2,N_2)体系。成矿流体在演化过程中经历了岩浆热液与大气降水的混合作用以及流体的沸腾作用,二者相结合打破化学平衡,是引起钨的化合物分解并沉淀的主要因素。并且盐度-热焓图解显示成矿流体演化过程是以混合作用为主导,局部发生沸腾作用。
The Shimen Si tungsten deposit in northern Jiangxi is a super-large tungsten polymetallic deposit discovered in recent years, which is likely to break the resource pattern of the traditional Jiangxi Nanchuanbei Copper. In order to reveal the characteristics of ore-forming fluid and to explore the fluid evolution process, the fluid inclusions in quartz-vein type ore-bearing quartz in Shimentou tungsten deposit were selected for petrography, microscopic temperature measurement and laser Raman spectroscopy . Petrographic observation shows that the Shimenji tungsten deposit is dominated by fluid-rich inclusions and another gas-rich phase, three-phase with CO_2, pure liquid phase and pure gas phase inclusions. The results of microscopic thermometry show that the mean temperature is between 147.1 ℃ and 316.2 ℃, and mainly lies in the range of 201.5 ℃ to 259.2 ℃ with an average of 211.1 ℃. The salinity w (NaCl_ (eq)) ranges from 0.88% to 7.31% With a mean value of 2.45%. The density distribution ranged from 0.79g / cm ~ 3 to 0.94g / cm ~ 3, concentrating at 0.82g / cm ~ 3 ~ 0.92g / cm ~ 3, 0.87g / cm ~ 3. In addition to the detection of CH_4, Raman analysis also detected the presence of CO_2 and N_2 to varying degrees. The results indicate that the ore-forming fluid is characterized by moderate temperature, low salinity and low density of NaCl-H 2 O-CH 4 ± (CO 2, N 2) system. During the evolution process, the ore-forming fluids have experienced the mixing of hydrothermal fluid and atmospheric precipitation and the boiling of fluids. The combination of the two can break the chemical equilibrium, which is the main factor that causes the decomposition and precipitation of tungsten compounds. And the salinity-enthalpy diagram shows that the evolution of ore-forming fluid is dominated by mixing and local boiling occurs.