| 造山型金矿研究进展:兼论中国造山型金成矿作用 |
| |
| 引用本文： | 王庆飞,邓军,赵鹤森,杨林,马麒镒,李华健.造山型金矿研究进展:兼论中国造山型金成矿作用[J].地球科学,2019,44(6):2155-2186. |
| |
| 作者姓名： | 王庆飞 邓军 赵鹤森 杨林 马麒镒 李华健 |
| |
| 作者单位： | 中国地质大学地质过程与矿产资源国家重点实验室, 北京 100083 |
| |
| 基金项目： | 国家重点研发计划项目2016YFC0600307国家重点基础研究发展计划"973"项目2015CB452606 |
| |
| 摘 要： | 造山型金矿指与大洋板块俯冲和陆块拼贴有关、产在汇聚板块边界变质地体内部或者边缘受韧-脆性断裂构造控制的,成矿流体以低盐度H2O-CO2-CH4为主要特征的,成矿深度(2~20 km)和温度(200~650℃)及其相应的蚀变矿化组合有较大变化的系列金矿床.造山型金矿形成与超大陆聚合时限具有一致性.由于围岩类型和控矿构造多样性、地球化学特征具有多解性、金属源区和演化的不确定性以及成矿就位和物质起源的空间差距,造山型金矿成因模式有以下两个主要观点.第一种为大陆地壳变质流体成因模式,认为造山型金矿形成于造山作用同变质阶段,并随岩石圈演化矿床的物质来源发生变化;富金流体的释放由上地壳岩石绿片岩相到角闪岩相的进变质作用导致,该过程中的黄铁矿向磁黄铁矿转变释放了大量的金,这种模式被广泛运用于赋存在绿片岩相中的显生宙造山型金矿.然而越来越多的实例证实造山型金矿主要形成于峰期变质的退变质阶段或者与区域变质没有任何关系,变质流体成因模式受到了强烈质疑;与大陆地壳变质模式相对立的是幔源流体模式,其认为流体起源于俯冲洋壳脱水或富集地幔再活化,不同时代和地区的成矿流体具有一致性;尽管该模式不符合传统的平衡条件下的相变原理,但是基于幔源流体的存在及其浅部运移的大量观测,初步认为成矿流体是在超临界和非平衡条件下完成了金属的幔→壳迁移.中国造山型金矿分布于江南造山带志留纪、天山-阿尔泰二叠纪、华北克拉通北缘三叠-侏罗纪、特提斯造山带二叠-侏罗纪、华南板块晚三叠世-侏罗纪、华北克拉通东南缘白垩纪、青藏高原及周缘古近纪等七大成矿带,主要受到了显生宙不同时代造山作用的控制,成矿时代晚于变质峰期,重要成矿带大型矿集区(胶东、哀牢山、扬子西缘)的实例解剖均支持幔源流体成因模式.
|
| 关 键 词： | 造山型金矿 地幔流体 变质流体 构造控矿 构造背景 矿床 |
| 收稿时间： | 2018-11-06 |
Review on Orogenic Gold Deposits |
| |
| Wang Qingfei,Deng Jun,Zhao Hesen,Yang Lin,Ma Qiyi,Li Huajian.Review on Orogenic Gold Deposits[J].Earth Science-Journal of China University of Geosciences,2019,44(6):2155-2186. |
| |
| Authors: | Wang Qingfei Deng Jun Zhao Hesen Yang Lin Ma Qiyi Li Huajian |
| |
| Affiliation: | (State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China) |
| |
| Abstract: | The orogenic gold deposits show features as follows:relation to oceanic plate subduction and terrane accretion, hosted by metamorphic massif along convergent plate boundaries, controlled by ductile to brittle shear zones, low salinity and H2O-CO2-CH4 dominating ore fluid, wide formation depths varying from about 2 to 20 km and formation temperatures ranging within 200-650℃, temperature-dependent alteration and ore mineral assemblages. Orogenic gold deposits formed coevally to the time of cycled convergences of supercontinents. Due to the diversity of wall rock types and ore-controlling structures, ambiguity of ore geochemistry, uncertainty of fluid and metal sources and their evolutions, and disparity between source regions and ore deposition locations, two distinct origin models were proposed for orogenic gold deposits. The first is metamorphic fluid model, in which the deposits formed in prograde metamorphism of orogeny with different source from evolving regional upper crust. The auriferous fluid is considered to release from greenschist-to amphibolite-facies prograde metamorphism of upper crustal rocks, during which gold and other metals are liberated from transformation of pyrite to pyrrhotite. This model was universally applied to Phanerozoic orogenic gold deposit shosted by greenschist-facies terranes. However, it was recognized that most orogenic gold deposits formed in retrogression stage subsequent to peak metamorphism or without any spatial-temporal link to regional metamorphism, which challenged the metamorphic fluid model. Thus the mantle fluid model, which indicates that ore fluids for orogenic gold deposits are derived from devolatilization of subducted oceanic plate or fertile mantle, was proposed. Although the mantle fluid model is not compatible with the petrological diagram in phase equilibrium condition, the extensive proofs for the existence of mantle fluids and their appearance near surface support that mantle fluids are capable to transport to upper crustal levels under supercritical conditions and phase unequilibrium. The Chinese orogenic gold deposits are divided into seven gold belts:Silurian belt along Jiangnan orogen, Permian belt in Tianshan and Altay orogen, Triassic to Jurassic one along northern margin of North China craton (Solonker orogen), Triassic to Jurassic one within Paleo-Tethyan orogens, Jurassic one along southern margin of South China block possibly controlled by the Paleo-Tethyan closure, Cretaceous one along southern margins of North China craton, and Paleogene one in Tibetan Plateau and its margins. Orogenic gold deposits in China formed in Phanerozoic in association with various orogeny, with ore-forming ages post dating peak metamorphism. Case studies on gold districts in these belts, such as Jiaodong, Ailaoshan, and western margin of Yangtze craton, all favored the mantle fluid model. |
| |
| Keywords: | orogenic gold deposit mantle fluid metamorphic fluid structural control tectonic setting deposits |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
|
点击此处可从《地球科学》下载全文 |
|
