论文部分内容阅读
紫木凼金矿床是黔西南微细浸染型(卡林型)金矿带上的一个代表性金矿床。本文对该矿床主成矿阶段(Ⅱ)石英和方解石以及晚成矿阶段(Ⅲ)方解石中的流体包裹体进行了岩相学和显微测温研究,结果表明,各成矿阶段包裹体类型有H2O包裹体、CO2包裹体、CO2-H2O包裹体、气相CH4包裹体和CH4-H2O包裹体5类,其中CO2包裹体和CO2-H2O包裹体只在主成矿阶段(Ⅱ)的石英中发育。主成矿阶段和晚阶段流体包裹体均一温度范围分别为180～220℃和100～180℃,盐度分别为0.35%～7.45% NaCl和0.18%～5.71% NaCl,密度分别变化于0.745～0.969 g/cm3和0.868～0.993 g/cm3,总体属于中低温、低盐度、中等密度的H2O-NaCl-CO2流体体系。矿床成矿过程是一个温度退缩、盐度降低、密度增大的过程。主成矿阶段H2O-NaCl-CO2流体发生不混溶作用,是导致矿质沉淀成矿的主要原因。CO2流体、CH4流体在金的成矿过程中起重要作用。
The Zimugu gold deposit is a representative gold deposit on the finely disseminated (Carlin-type) gold deposit in southwestern Guizhou. In this paper, petrographic and microscopic temperature studies of fluid inclusions in the quartz and calcite in the main metallogenic stage (Ⅱ) and calcite in the late metallogenic stage (Ⅲ) are carried out. The results show that the types of inclusions There are five types of inclusions: H2O inclusions, CO2 inclusions, CO2-H2O inclusions, gas-phase CH4 inclusions and CH4-H2O inclusions. Among them, CO2 inclusions and CO2- development. The homogenization temperatures ranged from 180 ℃ to 220 ℃ and from 100 ℃ to 180 ℃ in the main ore-forming stage and the late stage respectively. The salinity were 0.35% ~ 7.45% NaCl and 0.18% ~ 5.71% NaCl, respectively. The density varied from 0.745 to 0.969 g / cm3 and 0.868 ~ 0.993 g / cm3, which belongs to the medium-low temperature, low salinity and medium density H2O-NaCl-CO2 fluid system. The mineralization process is a process of temperature shrinkage, salinity reduction and density increase. In the main mineralization stage, H2O-NaCl-CO2 fluid is immiscible, which is the main reason that leads to mineralization and mineralization. CO2 fluid, CH4 fluid plays an important role in the gold mineralization process.