摘要
小秦岭石英脉型金矿主要产在华山、文峪等中生代花岗岩基南侧的太古宙荡泽河群绿岩带和早元古代滴沟群孔达岩系中。矿床地质特征和矿物包裹体及氢氦同位素研究证明矿床形成经历了Ⅰ期251～338℃变质热液矿化、Ⅱ期209～336℃变质热液—大气降水热液混合矿化和Ⅲ期155～178℃大气降水热液矿化。成矿元素富集特点及理论研究证明矿化主要发生在Ⅱ期,Ⅲ期贡献甚微。S、C、Pb同位素指示战矿物质来源复杂,并在成矿时高度均一化。综合讨论揭示出矿床形成于中生代华南与华北古大陆板块碰撞造山过程的陆内俯冲作用,可按碰撞造山成岩成矿模式指导进一步的找矿和研究。
The quartz vein type gold deposits of xiaoqinling area are mainly distributed south to the Mesozoic granite batholiths such as Wenyu and Huashan and entirely hosted in Archean greenstone belt of Dangzchc group and early Proterozoic Khondalite series of Shuidigou group. Geological characteristics of deposits, nature of fluid inclusions within minerals and isotopes of hydrogen and oxygen show that ore-forming process consists of three important epoches. Ⅰ, Ⅱ and Ⅲ cpoches are respectively mineralized at about 251-338℃ by metamorphic hydrothermal solution, at about 209-336℃ by mixed solution of metamorphic and meteoric hydrothermal solutions and at 155-178℃ by mete- oric hydrothermal solution. Concentration of ore-forming elements and theoretical re- search prove that mineralization is mainly contributed by epoch and negligibly by Ⅲ epoch. Complex source and intensive uniformizing during mineralization are demonstrated by isotopes of sulphur, carbon and lead. By comprehensive discussing, it is concluded that mineralization was caused by intracontinenal subduction during the Mesozoic prpgenesos collision orogeny between the Xouth and the North China plates. Further studyprospecting should be carried out according to the petrogenesis andmineralization model for collision orogeny proposed by Chen et al (1991).
基金
本文承国家自然科学基金
科学院矿床地球化学开放室基金资助
关键词
金矿床
石英脉型
矿化
地球化学
Xiaoqinling
gold deposit
quartz vein type
petrogencsis and mineralization model for collision orogeny
