【摘要】 为了了解抱伦金矿的成因条件,利用岩相学和拉曼光谱分析方法对不同期次含金石英脉中流体包裹体进行系统、深入的研究.结果表明,石英中流体包裹体可分为2种类型,即CO2-H2O包裹体和H2O溶液包裹体.CO2-H2O包裹体以CO2为主,含有CH4,主要存在于成矿期金-石英脉和金-多金属硫化物脉中,多为原生包裹体,孤立分布或成群分布,气液比变化大,显示不混溶流体包裹体组合特征.H2O溶液包裹体,主要存在于石英-碳酸盐脉中.显微测温结果显示,成矿期Ⅰ和成矿期Ⅱ包裹体的均一温度范围分别为248～376℃和213～320℃,成矿后流体包裹体的均一温度为140～244℃.成矿流体主要为CO2-H2O-NaCl热液体系,在成矿期Ⅰ和成矿期Ⅱ主要为中、低盐度(0.80%～16.05%NaCl equiv),并且富含挥发分(密度0.21～0.85g/cm3);在成矿期后,温度、盐度和CO2含量都相对降低;成矿晚期,方解石碳、氧同位素δ13 C(PBD,‰)和δ18 O(PBD,‰)分别在-6.86～-13.14和-10.64～-14.51之间,均指示流体主要以深源岩浆为特征,流体在运移过程中发生了水岩反应、蚀变,同时受到围岩有机质的混染.这种水岩反应以及由温度和压力降低所导致的不混溶作用可能是金矿金沉淀的主要因素.更多还原

【Abstract】 To better understand the formation of Baolun gold deposit and provide information for further exploration,fluid inclusions of quartz in gold-bearing quartz veins were investigated using Raman method.Our results showed that there were mainly two types of inclusion,i.e.,CO2-H2O and H2O,respectively.The former contained mainly CO2,with minor CH4,formed in the mineralization stage of gold-bearing quartz veins and gold multi-metal sulfide veins.These inclusions occurred in isolation or group with varied volume,and were the primary inclusion,exhibiting the characteristics of immiscible fluid inclusion.The later occurred mainly in quantz-calcite veins,containing pure H2O.The results of micro-thermometric measurement showed that the homogenization temperatures of mineralization periods Ⅰ and Ⅱ were 248-376℃ and 213-320℃,respectively.The homogenization temperature of the post-mineralization period fluid inclusion was 140-244℃.Ore-forming fluid was the CO2-H2O-NaCl hydrothermal system,mineralization periods Ⅰ and Ⅱ were dominantly mid-low salinities(0.8%-16.05% NaCl equiv) and rich in volatile component(density 0.21-0.85g/cm3).Temperature,salinity,and CO2 concentration all decreased in the late mineralization period.The calcite δ13C(PBD,‰) and δ18O(PBD,‰) values of the late stage veins were-6.86 to-13.14 and-10.64 to-14.51,respectively,indicating a magma origin in combination with fluid-rock reactions and organic mixing from the country rocks during the migration and transportation processes.Immiscibility due to water/rock reactions and decrease in fluid temperature and pressure was probably responsible for the gold deposition.更多还原