扬子克拉通前寒武纪基底对中生代大面积低温成矿的制约  

Control of the Precambrian basement on the formation of the Mesozoic largescale low-temperature mineralization in the Yangtze Craton

作　　者：胡瑞忠[1,2] 陈伟 毕献武 付山岭[1] 尹润生 肖加飞[1] HU Ruizhong;CHEN Wei;BI Xianwu;FU Shanling;YIN Runsheng;XIAO Jiafei(State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《地学前缘》2020年第2期137-150,共14页Earth Science Frontiers

基　　金：国家自然科学基金项目(41830432,U1812402);国家重点基础研究发展计划“973”项目(2014CB440900)。

摘　　要：大面积低温成矿主要见于扬子克拉通和美国中西部,且扬子克拉通比美国中西部具有更多的矿床类型,在全球极具特色,是建立大面积低温成矿理论的理想区域。前人对扬子克拉通中生代大面积低温矿作用进行了较系统的研究,在矿床地质特征、矿床物质组成、成矿流体特征、成矿时代和成矿动力学背景等方面,已取得重要进展。进一步的研究表明,扬子低温成矿域不同矿种的矿床组合(Pb-Zn、Au-Hg-Sb-As、Au-Sb等)在地理位置上是分区产出的,而这种不同矿床组合的分区对应着不同类型的前寒武纪基底。初步证据显示,扬子克拉通前寒武纪基底(含寒武纪)富含低温成矿元素,深循环流体浸取基底岩石中的成矿元素发生了大面积低温成矿,而基底岩石成矿元素组成的空间不均一分布则控制了不同区域矿床组合的差异。应指出的是,由于成矿金属元素来源示踪的复杂性,大面积低温成矿的物质基础尚需更系统的研究进一步证实。Large-scale low-temperature mineralization occurs throughout the Yangtze Craton and centralwestern USA,with the former containing more types of low-temperature deposit.In addition to the MVT Pb-Zn and Carlin-type Au-(As)-(Sb)-(Hg)-(Tl)deposits common to the central-western USA,the Yangtze Craton also contains numerous vein-type Sb,Hg,and As deposits,making it ideal for exploring lowtemperature mineralization formation models.Numerous studies have been conducted on the Mesozoic largescale low-temperature mineralization in the Yangtze Craton,and the deposit geology,ore components,oreforming fluids,timing,and geodynamic setting of mineralization are generally well understood.This study revealed that different deposit types(e.g.,Pb-Zn,Au-Hg-Sb-As,and Au-Sb)in the Yangtze Craton are not spatially associated but distributed in specific domains with distinct Precambrian basement rocks.There are some indications that the basement rocks are variably enriched with various metals.The metals are remobilized and transported by deep-circulating fluids responsible for late large-scale low-temperature mineralization.The specific distributions of different deposit types are likely mainly controlled by the spatial heterogeneity of ore-forming elements in the basement rocks of the Yangtze Craton.However,this interpretation requires further confirmation,as tracing the metal sources of low-temperature mineralization is highly complex.

关 键 词：扬子克拉通 前寒武纪基底 中生代大面积低温成矿 成矿金属元素来源 

分 类 号：P534.1[天文地球—古生物学与地层学] P611[天文地球—地质学]