新疆阿尔泰南缘克因布拉克铜锌矿床成矿流体的氦-氩同位素示踪  

Helium and Argon Isotopes Tracing for Sources of Ore-forming Fluid in the Keyinbulake Copper-zinc Deposit,Southern of Altay,Xinjiang

作　　者：张志欣[1,2] 杨富全[2] 蒋国豪[3] 刘锋[2] 李强[2] 耿新霞[2] 

机构地区：[1]中国科学院新疆生态与地理研究所,新疆矿产资源研究中心,新疆乌鲁木齐830011 [2]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点实验室,北京100037 [3]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵州贵阳550002

出　　处：《新疆地质》2014年第1期65-69,共5页Xinjiang Geology

基　　金：国土资源部公益性行业科研专项经费项目(200911007-06);国家科技支撑计划项目(2011BAB06B03-02);国家自然科学基金项目(41272103)联合资助

摘　　要：克因布拉克铜锌矿床赋存于二长花岗岩外接触带的上志留-下泥盆统康布铁堡组黑云石英片岩、变质石英砂岩中,矿体呈似层状、透镜状及脉状.本文对铜锌矿石中的黄铁矿流体包裹体氦和氩同位素组成进行了研究.黄铁矿中流体包裹体的4He 含量为0.241×10^-7-5.288×10^-7 cm^3STP/g,Rc/Ra 值为0.95-1.89,幔源He 的含量为14.1%-28.8%,表明成矿流体中氦主要来源于地壳,存在幔源氦的加入.40Ar 含量为4.345×10^-8-7.752×10^-8 cm^3STP/g,40Ar/^36Ar 比值变化于302.10-436.96,40Ar＊含量为2.2%-32.4%,表明成矿流体中存在含有放射性成因氩的大气降水加入.结合矿床地质特征及氢、氧、碳、硫同位素特征,认为成矿流体来源于高温深源壳幔混合成因的岩浆流体,具大气氩同位素组成特征的低温大气降水.The Keyinbulake copper-zinc deposit occurs as stratoid, lenticular and vein in the exocontact zones between monzogranite granite and Upper Silurian-Lower Devonian biotite quartz schist and metamorphic quartz sandstone of the Kangbutiebao Formation. In this paper, we analyzed the helium and argon isotopic composition of fluid inclusions in py-rite from chalcopyrite-sphalerite ores.The 4He content vary from 0.241×10-7cm3STP/g to 5.288×10-7cm3STP/g, the Rc/Ra ratios are 0.95 to 1.89, and the helium content which is derived from mantle vary from 14.1% to 28.8%, all of these char-acteristics showed that the helium in ore-forming fluid mainly derived from crust,with some contribution from mantle. The 40Ar content vary from 4.345×10-8 cm3STP/g to 7.752×10-8 cm3STP/g, the 40Ar/36Ar ratios are 302.10 to 439.96, and the 40Ar* content vary from 2.2% to 32.4%,indicated the existence of meteoric water in ore-forming fluid,which contain radioactive argon.Combining the geological characteristic of deposit, hydrogen,carbon and sulfur isotopic characteristics of the Keyinbulake copper-zinc deposit, suggested the ore-forming fluid were a mixture between high temperature crust-mantle derived magmatic fluid and low temperature meteoric water with similar argon isotopic characteristics of atmo-sphere.

关 键 词：阿尔泰 克因布拉克 氦和氩同位素 黄铁矿 成矿流体 

分 类 号：P618.4[天文地球—矿床学]