地球化学急变带与地幔柱资源系统  

Geochemical Steep Zones and Resource Systems of Mantle Plumes

作　　者：朱炳泉[1] 常向阳[1] 胡耀国[1] 张正伟[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640

出　　处：《矿物岩石地球化学通报》2003年第4期287-293,共7页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家重点基础研究发展规划项目(G19990432);中国科学院知识创新项目(KZCX2 SW 125)资助

摘　　要：地幔柱产生大面积软流圈上涌,沿深断裂形成岩浆房,导致大规模溢流玄武岩裂隙式喷发。良好的地幔柱成矿系统常出现在岩石圈不连续界面和三叉拼接裂谷,表现为地球化学急变带。地幔柱资源系统包括以下几方面:(1)地幔柱岩浆分异成矿系统,从封闭到开放环境的岩浆分异形成了富钛、富镁和低钛三个岩浆端员,构成了Cu Ni(PGE)硫化物、Fe Ti V氧化物和Cu Ag自然金属三个成矿体系;(2)地幔柱同生火山热液成矿系统,包括赤铁矿 阳起石 硅化氧化铜,沥青化 绿泥石 浊沸石化自然铜和碳酸盐化硫化物三个成矿体系;(3)地幔柱同构造盆地油气系统,巨量岩浆的快速成溢流导致地壳的快速沉降,形成同构造热盆地,具有油气前景;(4)地幔柱火山岩、硅质岩和富有机质砂页岩组合为优势生态体系提供了地质环境。Mantle plumes induced asthenosphere upwelling and development of magma chambers along deep-sited faults,and thus resulted in fracture eruption of flood basalts on large scale. The mantle plume with well developed metallogenic systems usually occurs on triple junction rifts with discontinuous lithosphere boundary and geochemical steep zones. Resource systems related to mantle plumes include: (1) the mineralization system of magma fractionation derived from three end members of enriched Ti, enriched Mg,and depleted Ti magmas that comprise Cu-Ni(PGE) sulfides, Fe-Ti-V oxides and native metals of Cu-Ag,respectively; (2)the mineralization system associated with synvolcanic hydrothermal activation,including Cu oxides with hematitization-actinoritization-silicification, (native) coppers with bituminization-chloritization-zeolitization and sulfides with carbonatization;(3) the oil-gas system developed in syntectonic basins and associated with rapid dipping of crust induced by huge quantity of magma eruption from mantle plumes;and (4) the volcanic, siliceous and carbonaceous argillitic rocks that provide a favorable geologic environment for development of dominant ecology system.

关 键 词：地幔柱 成矿系统 地球化学边界 地质环境 

分 类 号：P59[天文地球—地球化学]