滇西北羊拉铜矿床3175m中段铜矿石和构造岩地球化学特征及地质意义

羊拉铜矿床是金沙江缝合带内的典型代表性铜矿床,其矿体呈层状、似层状、脉状及透镜体状产出,且明显受断裂构造及层间破碎带控制。采用电感耦合等离子体质谱仪(ICP-MS)分析技术重点对羊拉矿床里农矿段深部3 175m中段铜矿石和断裂构造岩进行主量和微量-稀土元素组成研究。结果表明,铜矿石和各构造岩均富集CaO、Al₂O₃与TFe₂O₃;羊拉矿床NW向断裂可能与铜成矿作用无关。此外,断裂构造岩微量元素R型聚类分析和因子分析表明存在5个微量元素组合:1)围岩微量元素组合(Ba、Rb、REE、Th、Li、U、Be、Ga、Cs、Cr、Ta、V、Sc、Hf、Zr、Nb);2)地质意义不明元素(Sr);3)铜矿化中温成矿元素组合(Cu、Bi、Co、Ge);4)铅锌矿化中低温成矿元素组合(Zn、Cd、Pb、Ag、In、Sn、Ni、Tl)和5)高温成矿元素组合(Mo、W);表明羊拉矿床铜形成于高中低温各热液成矿阶段的成矿温度环境。稀土元素组成特征指示铜成矿作用可能主要与NE向断裂、近EW向断裂构造活动有关,而大理岩和绢云...

Geochemical characteristics of copper ore and tectonite in the underground tunnel 3 175 m section from the Yangla Copper deposit in northwest Yunnan and their geological implications

The Yangla copper deposit is a representative deposit in Jinshajiang suture zone.Its ore bodies are layered,vein-like and lenticular,and obviously controlled by structures and interlayer fracture zones.In this paper,Inductively Coupled Plasma Mass Spectrometry(ICP-MS)analytical technology was used to measure the major and trace-rare earth element compositions of copper ore and tectonite in the underground tunnel 3175 m section of the Linong ore block,Yangla copper deposit.The results showed that copper ore and various tectonites were enriched in CaO,Al₂O₃,and TFe₂O₃.The NW-trending fault of Yangla copper deposit may not be related to the copper mineralization.Furthermore,R-type cluster analysis and factor analysis showed that there were five trace element assemblages in tectonites:1)Assemblage of trace elements in wall-rock(Ba,Rb,REE,Th,Li,U,Be,Ga,Cs,Cr,Ta,V,Sc,Hf,Zr,and Nb);2)Geologically significance unknown trace element assemblage(Sr);3)Mesothermal metallogenic trace element assemblage(Cu,Bi,Co,and Ge);4)The moderate-low temperature metallogenic trace element assemblage(Zn,Cd,Pb,Ag,In,Sn,Ni,and Tl);5)The high-temperature metallogenic trace element assemblage(Mo and W).The above findings indicated that the copper of Yangla deposit was formed in various hydrothermal mineralization stages from high-medium-low temperature environments.The composition characteristics of rare earth elements indicated that copper mineralization may be mainly related to NE-trending faults and near-EW-trending faults,while the marble and sericite slate had less contribution to the copper mineralization in the Yangla copper deposit.The above-mentioned geochemical characteristics of copper ore and tectonite can provide theoretical guidance for further mineral exploration in the Yangla copper deposit.