华北克拉通壳幔演化与胶东巨量金成矿作用  

The secular crust-mantle evolution of the North China Craton and the formation of giant Jiaodong gold deposits

作　　者：汪在聪 汪翔 宗克清[1] 程怀 王焰[3] 李建威 杨进辉[5] WANG Zai-cong;WANG Xiang;ZONG Ke-qing;CHENG Huai;WANG Christina Yan;LI Jian-wei;YANG Jin-hui(State Key Laboratory of Geological Processes and Mineral Resources,School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China;Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou 510075,China;CAS Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;State Key Laboratory of Geological Processes and Mineral Resources,School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]中国地质大学(武汉)地球科学学院,地质过程与矿产资源国家重点实验室,武汉430074 [2]中国地质调查局广州海洋地质调查局,广州510075 [3]中国科学院广州地球化学研究所,中国科学院矿物学与成矿学重点实验室,广州510640 [4]中国地质大学(武汉)资源学院,地质过程与矿产资源国家重点实验室,武汉430074 [5]中国科学院地质与地球物理研究所,岩石圈演化国家重点实验室,北京100029

出　　处：《矿物岩石地球化学通报》2023年第6期1231-1247,I0001,共18页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(42273023,41722302);国家重点研发计划重点专项项目(2016YFC0600103)。

摘　　要：华北克拉通胶东半岛在早白垩世爆发性地形成了巨量金矿床,金的来源和成矿过程一直备受关注。本文从金等亲铜元素的地球化学行为和储库出发,剖析华北克拉通的壳、幔长期演化与大规模金成矿之间的时空-成因联系。华北克拉通前寒武地壳基底因早期高级变质作用亏损金,中生代成矿前的花岗(闪长)岩的金丰度也非常低,表明地壳岩石难以为胶东大规模金成矿作用提供主要金属。大量研究表明,受俯冲交代的地幔控制着胶东金成矿,交代作用使亏损地幔具有与饱满地幔类似的金含量,并补充了大量的水和硫等挥发分,有助于形成幔源富挥发分岩浆并促进金的释放。华北克拉通交代地幔在长期演化过程中并未出现金的异常富集,地幔源区和幔源岩浆的金属显著富集并非形成超大型金矿省的必要条件。在克拉通破坏的强烈伸展背景下,富含金和挥发分的幔源岩浆以及后续的岩浆热液演化过程,特别是末端效应,在大规模胶东金成矿作用中扮演着非常重要的角色。The giant Jiaodong gold deposits in the eastern part of North China Craton(NCC)were formed extensively during Early Cretaceous.The sources of gold and specific processes for such intensive gold mineralization have been paid much attention by researchers.Regarding the geochemical behaviors and reservoirs of chalcophile elements including Au,in this study,we have evaluated the spatial and temporal associations and genetic relationship between the secular evolution of crust and mantle rocks and the formation of giant gold deposits in the NCC.Because of the high-grade metamorphism of the Precambrian crustal basement in the early stage,gold of the basement rocks in the NCC was strongly depleted.In addition,the pre-mineralization Mesozoic granitoids(granodiorite)also have very low Au contents.Consequently,the gold-barren crustal rocks could not serve as the main gold source for the Jiaodong gold deposits.Numerous studies have shown that the mantle resulted from the subduction had controlled the formation of Jiaodong gold deposits.The metasomatism made the depleted mantle elevate a gold content similar to that of the fertile mantle,and replenished substantial volatiles such as water and sulfur into the mantle,which contributed to the formation of mantlederived volatile-rich magma and promoted the efficient release of gold.There is no remarkable enrichment of gold in the mantle of the NCC during the secular evolution.Anomalous gold enrichment in the metasomatized SCLM and the mantlederived magmas is thus not the prerequisite for the formation of giant gold province.Under the strong lithosphere extension background of the intensive decratonization,mantle-derived magmas enriched in gold and volatiles and the subsequent magmatic-hydrothermal evolution process,especially the late-stage ore-forming processes,could have played a particularly important role in the formation of large-scale Jiaodong gold deposits.

关 键 词：华北克拉通 岩石圈地幔 俯冲交代作用 金成矿 挥发分 

分 类 号：P612[天文地球—矿床学]