【摘要】 文章在分析甘肃西成盆地小沟里—三羊坝金矿床地质特征的基础上,研究了矿床地球化学、稳定同位素的特征。结果表明,大部分黄铁矿的Co/Ni比值大于1,反映成矿物质主要来自于岩浆热液;稀土总量w(REE)=6.07×10-6~227.20×10-6,LREE/HREE=1.372~4.582,轻稀土富集;在稀土元素标准化模式图中,围岩、矿石、含金石英脉的稀土配分型式相似,呈平缓的右倾特征,具有弱的铕负异常;硫同位素δ(34S)=-6.15×10-3~+13.62×10-3,显示多源的特征;铅同位素组成显示铅为壳幔混合源;包裹体主要为气液两相,液相成分中的阳离子以Na+和K+为主,阴离子主要为Cl-,气相成分以H2O和CO2为主;包体的均一温度为115~205℃,盐度为7.2%~11.5%;成矿流体以大气降水为主。更多还原

【Abstract】 On the basis of detailed investigation of geological setting and ore deposit features,this paper deals with geochemistry and sulfur and lead isotopes of Xiaogouli-Sanyangba gold deposit in Xihe-Chengxian basin,Gansu province.The results show that the Co/Ni of pyrite is mostly more than 1 indicating that the ore-forming material is derived from magmatic-hydrothermal fluid.The total REE and LREE/HREE from 6.07×10-6 to 227.20×10-6,and from 1.372 to 4.582 with light REE enrichment.The REE pattern of surrounding rocks is similar to that of ores and gold-bearing quartz veins.The normalized REE pattern is gently right inclined with weak Eu negative anomaly.The sulfur isotope composition is δ(34S) from-6.15×10-3 to +13.62×10-3 with typical multi-resource signature of fluid.The lead isotope composition is of the mixed crust-mantle origin.Mineral inclusions is mainly in 2 phases,gas and liquid.Analysis showed that in liquid pahse Na+,K+ are the dominant cation and Cl-the dominant anion,in gas phase H2O and CO2 dominant.The homogenization temperature,salinity range in 115 ℃ to 205 ℃ and 7.2% to 11.5% respectively.The ore fluid is mainly composed of meteoric water.更多还原