皖赣沿江地区中生代壳幔相互作用与多成因夕卡岩成矿过程研究综述  

A review on the Mesozoic crust-mantle interaction and metallogeny of various skarn deposits in the Jiangxi-Anhui segment along the Yangtze River

作　　者：杜杨松[1] 曹毅[1] 秦新龙[2] 庞振山[3] 杜轶伦[3] 王功文[1] DU Yangsong;CAO Yi;QIN Xinlong;PANG Zhenshan;DU Yilun;WANG Gongwen(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;East China Mineral Exploration and Development Bureau for Non-Ferrous Metals,Nanjing 210007,China;Development and Research Center,China Geological Survey,Beijing 100037,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]江苏省有色金属华东地质勘查局,江苏南京210007 [3]中国地质调查局发展研究中心,北京100037

出　　处：《地学前缘》2020年第2期165-181,共17页Earth Science Frontiers

基　　金：国家自然科学基金项目(41730426,41030423);中国地质调查局地质调查项目“整装勘查区矿产地质调查与找矿预测”(WKZB1911BJM300369/003)。

摘　　要：在皖赣沿江地区分布着大量中生代侵入岩体及其岩石包体和相关的夕卡岩矿床。本文在综合整理作者研究团队近30年来所获得的区内大部分侵入岩体及其岩石包体和夕卡岩矿床研究资料的基础上,聚焦区域中生代壳幔相互作用与多成因夕卡岩成矿过程分析,为发展壳幔成矿学打下一定基础。基性侵入岩和镁铁质岩石包体的同位素年代学和岩石地球化学资料表明,皖赣沿江地区在中生代发生了碰撞后(145~135Ma)富铜金和造山后(130~120 Ma)富铁金幔源岩浆底侵作用和相应的壳幔混源岩浆作用。壳幔混源岩浆作用主要包括结晶分异作用、同化混染作用、岩浆混合作用和岩浆熔离作用。夕卡岩矿床地质调研和镜下观察结果显示,两期壳幔混源岩浆侵入晚古生代到早中生代围岩地层后引发了多成因夕卡岩成矿作用,形成了接触交代、层控、岩浆和复合叠加等多成因夕卡岩矿床。接触交代、层控、岩浆和复合叠加夕卡岩矿床分别以热液交代、沉积+热液交代、岩浆结晶+热液交代和沉积+岩浆结晶+热液交代矿物组合和结构构造为特征。在碰撞后酸性-中酸性侵入岩体中产有富Cu和Zn等成矿物质的元古宙变质岩包体,表明碰撞后富铜金的底侵玄武岩浆或其演化岩浆在浅位岩浆房中同化了元古宙变质基底成矿物质(铜锌等)储库导致铜进一步富集,从而形成更富铜的酸性-中酸性岩浆。在碰撞后中基性-基性侵入岩体中产有含大量Cu-Fe硫化物(黄铜矿和磁黄铁矿)和氧化物包裹体的深位和浅位堆积岩,表明碰撞后富铜金的底侵玄武岩浆在深位岩浆房中和其演化岩浆在浅位岩浆房中发生了强烈的结晶分异作用导致铜铁亏损,形成更富金的中基性-基性岩浆。酸性-中酸性侵入岩体中夕卡岩包体和夕卡岩中辉长岩-夕卡岩过渡包体的存在表明,碰撞后富铜金的底侵玄武岩浆在侵位处同化�A large number of Mesozoic intrusions,their enclaves and related skarn ore deposits are distributed along the Yangtze River.We present thirty years of our study on Mesozoic intrusions with xenoliths and associated skarn deposits in the Jiangxi-Anhui segment along the Yangtze River.Specifically,this paper focuses on the analysis of the Mesozoic crust-mantle interaction and metallogeny of various skarn deposits in the area in order to lay some foundation for the development of crust-mantle metallogeny.Isotopic chronological and petro-geochemical data of the basic intrusive rocks and mafic xenoliths confirm the occurrence of underplating of the post-collisional mantal-derived magma(145-135 Ma) rich in Cu and Au,and the post-orogenic mantal-derived magma(130-120 Ma) rich in Fe and Au.In addition,the existence of similar activities of magma from the mantle with crust in the Mesozoic can be confirmed from the data.The activities of magma from the mantle with crust mainly include crystalline fractionation,assimilation and contamination,magma mixing,and magma liquation.Geological investigation and microscopic observation of skarn deposits show that the two episodes of intrusions of various mantle-derived magmas with crust into Late Paleozoic to Early Mesozoic wallrock strata led to mineralization of various skarns responsible for the formation of various skarn deposits,including contact replacement,stratabound,magma,and compound and superimposed skarn deposits.These deposits are characterized by distinct types of mineral assemblage and texture as well as the structure of hydrothermal replacement,sedimentationhydrothermal replacement,magma crystallization-hydrothermal replacement,and sedimentation-magma crystallization-hydrothermal replacement,respectively.The existence of the xenoliths of Proterozoic metamorphic rocks,rich in ore-forming materials such as Cu and Zn in the post-collisional acidic to intermediate-acidic intrusions,supports contamination of the Proterozoic metamorphic basement in the shallow-level magma cha

关 键 词：壳幔相互作用 夕卡岩矿床 成矿过程 中生代 皖赣沿江地区 

分 类 号：P611[天文地球—矿床学] P588.312[天文地球—地质学]