新疆三岔口铜矿床成矿流体性质及成因  

The Mineralizing Fluid Characteristics and Genesis of the Sanchakou Copper Deposit in Xinjiang

作　　者：孙燕[1] 肖渊甫[1] 李凤春[1] 熊发挥[1] 王祝彬[1] 

机构地区：[1]成都理工大学,成都610059

出　　处：《地质与勘探》2009年第3期235-239,共5页Geology and Exploration

基　　金：国家科委科技攻关项目(编号:96-915-05-04-01B);矿物学岩石学矿床学国家重点(培育)学科建设项目(编号:SZD0407)资助

摘　　要：三岔口铜矿床含矿岩体为海西中期的斜长花岗斑岩，矿体受构造控制。流体包裹体以气-液型为主，气液比较小，变化介于3％～7％之间。均一温度为140～280℃，成矿流体为低盐度、中低温热液。在成矿过程中随着硫化物的形成硫逸度降低，流体由弱酸性变为中性直至最后成为弱碱性。矿石硫同位素组成显示出幔源硫的特征，石英脉氧同位素组成表明成矿后期大量地下水加入成矿热液。矿石铅同位素组成为异常铅，富集放射成因^206Ph和^208Pb，样品线性关系良好，具壳-幔混合成因的特点，成矿模式年龄为245Ma。成矿物质主要来源于岩浆活动，同时与地壳物质的加入也有密切的关系。该矿床为与中深成相形成的斜长花岗斑岩有关的中-低温（岩浆-地下水）热液交代-充填型铜（钼）矿床。The copper mineralization at Sanchakou is related with a plagiogranite porphyry of Carboniferous age, and the ore-bodies are mainly controlled by fault structures. The fluid inclusion study shows that the inclusions are dominated with gas-liquid type with low gas to liquid ratio, varying between 3% to 7%. The homogenization temperatures of the fluid inclusions change between 140℃ to 280℃. The ore-formig-fluid is considered to be medium-low temperature hydrotherrnal liquid with low salinity. The sulphur isotope compositions of the ore have the characteristics of the mantle source. The oxygen isotope compositions of the quartz veins in the deposit indicate that a vast amount of meteoric water added to the ore-forming-solution during the late stage of mineralization. The lead isotope compositions of the ore are abnormal lead and rich in radiogenic 206Pb and 208Pb, the samples show a good linear relationship and have the genesis feature of mixed crustal and mantle origin, and ore-forming model age is 245Ma. The ore is mainly magmatic source but also closely related with the adding of crustal material. It is considered that the deposit is a medium-low temperature （ magma-meteoric water） hydrothermal replacement-infill type related with the mesogene of plaglogranite porphyry.

关 键 词：新疆 三岔口 铜矿床 成矿流体 成因 

分 类 号：P618.41[天文地球—矿床学]