滇西昌宁-孟连缝合带铜厂街矿床成因探讨  

Genesis of Tongchangjie deposit in Changning-Menglian suture zone,western Yunnan

作　　者：陈莉[1] 王立全[1] 王保弟[1] 刘函[1] 

机构地区：[1]成都地质矿产研究所,四川成都610081

出　　处：《矿床地质》2015年第3期617-631,共15页Mineral Deposits

基　　金：国家重点基础研究发展规划项目(编号:2009CB421003);国家自然科学基金(编号:41073033);中国地质调查局项目(编号:1212011121259;1212011085119)联合资助

摘　　要：铜厂街矿床位于昌宁-孟连缝合带北端,是一个以铜为主的小型矿床。含矿岩系为下石炭统平掌组下段一套变质拉斑玄武岩系列的海相火山岩组合。矿体呈层状、似层状产出,与围岩界线清晰。网脉状矿化发育于块状矿体之下。矿区含矿玄武岩主量、微量元素分析结果显示其具有N-MORB型洋脊玄武岩的特征;电子探针分析结果显示,黄铁矿主要落入岩浆热液型黄铁矿区;磁铁矿主要落入岩浆岩磁铁矿向沉积变质磁铁矿过渡区,且不同晶型、粒度的磁铁矿及其中心和边部在成因上都呈现出一定的差异和规律性。矿区石英和方解石中气液包裹体分析结果表明,均一温度范围131-362℃,盐度w（NaCleq）为2.07%-9.34%。结合矿区成矿地质特征,认为铜厂街矿床为与海底火山活动有关的VMS矿床,后经历了喜马拉雅期的变质改造。Located in the northern part of Changning-Menglian suture zone, the Tongchangjie deposit is a small copper deposit. Stratified and stratoid orebodies are hosted in the lower part of Pingzhang volcanic rocks. There is a clear boundary between the orebody and the wall rock. Stockwork mineralization is under the massive orebodies. The major and trace element analyses of basalts in Tongchangjie indicate that the basalts belong to N-MORE type basalts. The sample points of pyrite mostly fall in the magmatic hydrothermal pyrite region, whereas the sample points of magnetite mostly fall in the transition zone of magmatic magnetite to sedimentary metamorphic magnetite. The homogenization temperatures of fluid inclusions in quartz and calcite are in the range of 131-362℃, and the salinities w（NaCleq） vary in the range of 2.07%-9.34%. In combination with metallogenic geological characteristics, the authors hold that the Tongchangjie deposit was originally a VMS copper deposit related to submarine volcanic activities and later experienced metamorphic deformation in the Himalayan period.

关 键 词：地质学 玄武岩 电子探针 流体包裹体 VMS型 铜厂街 滇西 

分 类 号：P618.41[天文地球—矿床学]