安徽庐枞盆地井边地区脉状铜矿成矿流体特征与成矿过程研究  

Characteristic of ore-forming fluids of vein-type copper deposits in the Jingbian area of Lujiang-Zongyang volcanic basin in Anhui Province and its implications for mineralization

作　　者：魏国辉[1] 杜玉雕[1] 赵文广[1] 张赞赞[1] WEI Guo-hui;DU Yu-diao;ZHAO Wen-guang;ZHANG Zan-zan(Geological Survey of Anhui Province,Hefei 230001,China)

机构地区：[1]安徽省地质调查院,合肥230001

出　　处：《华东地质》2018年第2期116-125,共10页East China Geology

基　　金：中国地质调查局"安徽庐江矾山-枞阳周潭地区深部找矿靶区验证与评价(编号:12120114012701)"项目资助

摘　　要：庐枞盆地是长江中下游成矿带重要的矿集区之一,盆地内发育众多脉状铜矿床(点)。文章以井边地区的张家店铜矿、井边铜矿、周洼铜矿和虎栈铜矿为研究对象,分析井边地区脉状铜矿成矿流体特征,探讨脉状铜矿的成矿机制。研究表明:该区流体包裹体主要为气液两相包裹体,偶见纯液相包裹体和纯气相包裹体,流体系统为H2O-NaCl型。流体包裹体显微测温结果显示,成矿流体具有中温(220~240℃)、中低盐度(8wt%~20wt%)、低密度(0.86~1.16g/cm^3)的特征,流体体系沸腾作用不强。岩浆热液与大气降水的混合作用使成矿物质在岩体及围岩裂隙中析出、沉淀并富集成矿,形成受断裂控制的脉状铜矿床。The Lujiang-Zongyang volcanic basin in Anhui Province is one of the important ore cluster regions in the Middle-Lower Yangtze metallogenic belt,which hosts many vein-type copper deposits（points）.In this study,four vein-type copper deposits at Zhangjiadian,Jingbian,Zhouwa and Huzhan in the Jingbian area were chosen to study the characteristics of ore-forming fluids in order to preliminarily understand the metallogenic mechanism of vein type copper deposits.The study shows that fluid inclusions in the deposits are dominated by two-phase gas-liquid inclusions,occasionally with gaseous inclusions and pure liquid inclusions,suggesting that fluid system belongs to a H2 O-NaCl system.The microthermomentric analyses of the fluid inclusions show that the ore-forming fluids are characterized by mediumtemperature（220-240 ℃）,low-medium salinity（8 wt% -20 wt%）and low density（0.86-1.16 g/cm^3）,indicating that the ore-forming fluid experienced weak fluid-boiling.It can be concluded that mixing between magmatic water and meteoric water resulted in extraction,precipitation and enrichment of the oreforming materials in the fractures of rock mass and country rocks,thus forming fault-controlled vein-type copper deposits.

关 键 词：庐枞盆地 井边地区 流体包裹体 脉状铜矿床 成矿机制 

分 类 号：P618.41[天文地球—矿床学]