【摘要】 易门铜厂矿床存在两种不同成因矿石类型,一种是沉积成岩型铜矿石,另一种是热液脉状型铜矿石。以沉积成岩型矿石脉石矿物白云石和热液脉型矿石的脉石矿物石英、方解石为研究对象,采用ICP-MS方法分析稀土元素地球化学特征,深入阐明两种矿化类型的成矿作用特征。结果显示:矿区白云石∑REE处于正常海相碳酸盐范围内,LREE富集,贫HREE,δEu为0.54⁰.94,均值为0.76,反映沉积环境为弱酸性还原环境;方解石∑REE总量为14.57×10^-693.53×10^-6,石英∑REE总量为0.62×10^-641.44×10^-6,稀土元素都呈轻稀土富集型的右倾模式,Eu呈负异常,指示流体可能与富CO₂的地幔流体有关。铜厂矿床不同成因类型铜矿石中白云石、石英和方解石的稀土元素特征基本一致,表明成矿流体和白云岩的REE有继承演化的特点。更多还原

【Abstract】 Mineral deposit of Yimen Copper Factory has two different genesis ore types,one is the sedimentary diagenetic type copper ore and another is the hydrothermal vein type copper ore.Take the dolomite which is the gangue mineral of sedimentary diagenetic type ore and the quartz and calcite which are the gangue mineral of hydrothermal vein type ore,utilize the ICP-MS method to analyze the geochemical characteristics of rare earth element,illustrate the mineralization characteristics of two mineralization types.Results show that the∑ REE of dolomite in the mine area is within the normal range of marine carbonate,LREE is enriching,HREE is leaning,δEu is 0.54⁰.94,average value is 0.76 it means that the sedimentary environment is weakly acidic reducing environment;the total quantity of∑ REE of calcite is 14.57×10^-693.53×10^-6,the total quantity of∑ REE of quartz is 0.62×10^-641.44×10^-6,the rare earth element shows the right-leaning model of light rare earth element enrichment type,Eu shows the negative anomaly,it indicates the flow may has relationship with mantle fluid which enriching CO₂.The rare earth element characteristics of dolomite,quartz and calcite of different type copper ore in the mineral deposit of Copper Factory are basically the same,it means the REE of ore-forming fluid and dolomite has the characteristic of inheritance evolution.更多还原