新疆阿尔泰巴斯铁列克钨多金属矿矿物特征及其地质意义

巴斯铁列克是在新疆阿尔泰发现的首例中型钨多金属矿床。该矿床赋存于黑云二长花岗岩外接触带的上志留统—下泥盆统康布铁堡组火山沉积岩系中。矿体呈似层状和透镜状分布于矽卡岩中。矽卡岩及金属矿物特征关系到成矿机制研究和矿床模型的构建。文章对矽卡岩矿物和矿石中金属矿物进行了研究,电子探针分析表明,辉石端员组分以透辉石为主,少量钙铁辉石(w(Wo)为49.14%～50.71%,w(En)为24.38%～27.76%,w(Fs)为22.29%～24.27%);石榴子石以钙铝榴石为主;黑云母为铁云母,长石为正长石,绿帘石具有富Ca、Al、贫Fe特征。闪锌矿为铁闪锌矿,磁黄铁矿、黄铜矿、黝锡矿、毒砂、自然铋、辉银矿分子式与标准矿物基本一致。研究表明,矿区矽卡岩为交代成因的钙质矽卡岩,是岩浆热液交代大理岩的产物。通过对矿床地质特征、矽卡岩矿物组合、矽卡岩与矿化关系和矿物成因研究,提出成矿过程经历了早期矽卡岩阶段、退化蚀变阶段和石英硫化物阶段,钨矿化主要形成于退化蚀变阶段,铜锌矿化则形成于石英硫化物阶段。

Mineral characteristics of Basitielieke W-polymetallic deposit in Altay of Xinjiang and their geological significance

The medium-tonnage Basitielieke deposit is the first W polymetallic deposit discovered in Altay, Xinjiang. The discovery of the Basitielieke deposit is of great significance. It is hosted in the meta-volcano-sedimentary rocks of the Upper Silurian-Lower Devonian Kangbutiebao Formation which is located along the external contact zone of biotite monzonite. Orebodies occur in stratoid and lenticular forms in skarn. The mineral characteristics of the skarn and metal mineralogy are related to the study of metallogenic mechanism and the construction of the deposit model. Metal and skarn mineralogical characteristics were analyzed by electron microprobe. According to the results ob-tained, pyroxenes are mainly diopsides with minor hedenbergites (w(Wo)=49.14%~50.71%, w(En)=24.38%~27.76%, w(Fs)=22.29%~24.27%); garnets are grossular-dominated; biotites and feldspar are mainly iron micas and orthoclases, respectively; epidotes are characterized by high Ca, Al and low Fe concentrations. The sphalerite is mainlymarmatite, and themolecularformulas of pyrrhotite, chalcopyrite, stannite, arsenopyrite, bismuth and argentite are generally consistent with those of standard minerals. Compositions of these skarn minerals suggest that they are metasomatic calcic skarn derived from metasomatism between magmatic-hydrothermal and marble. Combined with deposit characteristics, skarn and mineral genesis and relationship between skarn and mineralization, the authors hold that the ore-forming processes can be divided into prograde stage, retrograde stage and quartz-sulfide stage, in whichW and Cu-Zn mineralizations were mainly formed in retrograde and quartz-sulfide stages, respectively.