Hydrothermal ore deposits in collisional orogens

作     者：Yongfei Zheng Jingwen Mao Yanjing Chen Weidong Sun Pei Ni Xiaoyong Yang 

作者机构：Key Laboratory of Crust-Mantle Materials and Environments Chinese Academy of Sciences School of Earth and Space Sciences University of Science and Technology of China Key Laboratory of Metallogeny and Mineral Assessment Ministry of Natural Rescources Institute of Mineral Resources Chinese Academy of Geological Sciences Key Laboratory of Orogen and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Key Laboratory of Marine Geology and Environment Center of Deep-Sea Research Institute of Oceanology Chinese Academy of Sciences State Key Laboratory for Mineral Deposits Research Institute of Geo-Fluids School of Earth Sciences and Engineering Nanjing University 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2019年第64卷第3期

页      面：205-212页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB18020303) the National Key Basic Research Progam of China (2015CB856100) 

主　　题：Ore deposits Hydrothermal fluid Accretionary orogen Collisional orogen Rifting orogen Tectonic reactivation 

摘      要：Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.