金顶超大型铅锌矿床中的地幔流体现实踪迹与壳幔混染叠加成矿机制  

Actual traces of mantle fluid of Jinding super-large Pb-Zn deposit and the mechanism of crust-mantle overlapping mineralization

作　　者：李春辉[1] 刘显凡[1,2] 赵甫峰[1] 卢秋霞[1] 吴冉[1] 王艳艳[1,3] 楚亚婷[1] 肖继雄[1] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国地质大学地质过程与矿产资源国家重点实验室,湖北武汉430074 [3]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《地学前缘》2011年第1期194-206,共13页Earth Science Frontiers

基　　金：国家自然科学基金项目(40773031;40473027);中国地质大学地质过程与矿产资源国家重点实验室开放基金项目(GPMR2007;GPMR0509);成都理工大学矿物学;岩石学;矿床学国家重点(培育)学科建设项目(SZD0407)

摘　　要：通过对金顶超大型铅锌矿床的砂岩型矿石和角砾岩型矿石较为系统的岩相学、电子探针、扫描电镜和能谱分析,初步揭示了黑色不透明物质为赋载成矿物质的主体,其本质为不均匀混溶硫化物和硅酸盐的碳酸盐熔浆快速冷凝的超显微隐晶固体,是地幔流体作用的现实微观踪迹。结合矿石矿物铅同位素组成的壳幔混染渐变特点及流体包裹体稀有气体同位素组成的壳幔混合特征进行的综合研究表明,与富碱岩浆成岩成矿背景相关的地幔流体自身携带成矿物质沿深大断裂向上运移并以交代蚀变引发壳幔混染叠加的方式参与地壳中的成矿作用,这是形成金顶超大型铅锌矿床的重要地球化学机制。On the basis of the studies of sandstone-type and brecciola-type ores from Jinding super-large lead-zinc deposit in western Yunnan Province by systematically using petrography,electron microprobe,scanning electron microscopy and energy spectroscopy,and combined with the studies of isotopic geochemistry,we confirmed that the black opaque cements are the micro-products of speedily cooling of carbonatite melt which mixed heterogeneously with sulfides,and that they are the relic actual traces of mantle fluid contaminated with crustal fluid.The crust-mantle transitive characteristics of noble gases in fluid inclusions from ore minerals suggested that during the transportation and mineralization processes of mantle fluid,the crustal fluid had made great contribution.The distribution style of Pb isotope provides a new understanding of the behaviors of Pb isotope in the crust-mantle overprinted processes.We propose the main geochemical mechanism of the Jinding lead-zinc deposit as follows： the mantle fluid derived from alkali-rich porphyry transported along deep faults,metasomatically altered host rocks and was overprinted by crustal fluids.

关 键 词：金顶铅锌矿床 岩相学 地幔流体踪迹 同位素地球化学 壳幔混染叠加 

分 类 号：P611[天文地球—矿床学]