| 东昆仑造山带东段晚古生代—早中生代构造岩浆演化与成矿作用 |
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| 引用本文： | 陈国超,裴先治,李瑞保,李佐臣,裴磊,刘成军,陈有炘,王盟,高峰,魏均启.东昆仑造山带东段晚古生代—早中生代构造岩浆演化与成矿作用[J].地学前缘,2020,27(4):33-48. |
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| 作者姓名： | 陈国超 裴先治 李瑞保 李佐臣 裴磊 刘成军 陈有炘 王盟 高峰 魏均启 |
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| 作者单位： | 1.南阳理工学院 土木工程学院, 河南 南阳 4730002.长安大学 地球科学与资源学院; 西部矿产资源与地质工程教育部重点实验室; 自然资源部岩浆作用成矿与找矿重点实验室, 陕西 西安 7100543.自然资源部稀土稀有稀散矿产重点实验室, 湖北 武汉 430034 |
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| 基金项目： | 国家自然科学基金项目(41872233);国家自然科学基金项目(41872235);国家自然科学基金项目(41802234);国家自然科学基金项目(41602229);青海省国土资源厅-中国铝业公司公益性区域地质矿产调查基金项目(200801);自然资源部稀土稀有稀散矿产重点实验室开放基金资助项目(KLRM-KF201902) |
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| 摘 要： | 东昆仑造山带位于中央造山系西段,在长期的地质演化过程中构造岩浆活动频繁,其中晚古生代—早中生代岩浆活动与成矿关系最为密切。本文系统总结了东昆仑造山带晚古生代—早中生代岩浆岩的分布、演化和成因,对典型矿床的地质特征进行分析,探讨东昆仑东段晚古生代—早中生代构造岩浆演化与成矿作用的联系。东昆仑晚古生代—早中生代构造岩浆演化可分为俯冲阶段(277~240 Ma)、同碰撞阶段(240~230 Ma)和后碰撞阶段(230~200 Ma),壳幔岩浆混合作用贯穿于古特提斯构造演化全过程。镁铁质岩浆岩主体为受俯冲流体交代的地幔部分熔融,花岗质岩浆岩主体为幔源岩浆底侵镁铁质下地壳部分熔融形成。东昆仑造山带东段俯冲阶段壳幔岩浆混合作用不仅带来成矿物质,使部分元素含量增高,还带来热源;经过成矿流体物理化学条件改变,导致大量矿物质沉淀,形成矿床,主要成矿金属组合为Cu、Mo、Au,矿床规模相对较小;同碰撞阶段由于受到挤压应力,岩浆岩出露较少,矿床多沿大型断裂带分布,主要成矿金属组合也以Cu、Mo、Au为主;后碰撞阶段由于岩石圈地幔拆沉,东昆仑整体处于拉张环境,为地幔物质参与成矿和成矿流体运移提供了通道。特别是同碰撞和后碰撞的转换阶段,是东昆仑造山带东段晚古生代—早中生代的主要成矿期,主要成矿金属组合为Cu、Pb、Zn、Fe。
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| 关 键 词： | 东昆仑东段 晚古生代—早中生代 岩浆演化 岩浆混合 成矿作用 |
| 收稿时间： | 2019-11-05 |
Late Palaeozoic-Early Mesozoic tectonic-magmatic evolution and mineralization in the eastern section of the East Kunlun Orogenic Belt |
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| CHEN Guochao,PEI Xianzhi,LI Ruibao,LI Zuochen,PEI Lei,LIU Chengjun,CHEN Youxin,WANG Meng,GAO Feng,WEI Junqi.Late Palaeozoic-Early Mesozoic tectonic-magmatic evolution and mineralization in the eastern section of the East Kunlun Orogenic Belt[J].Earth Science Frontiers,2020,27(4):33-48. |
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| Authors: | CHEN Guochao PEI Xianzhi LI Ruibao LI Zuochen PEI Lei LIU Chengjun CHEN Youxin WANG Meng GAO Feng WEI Junqi |
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| Institution: | 1. School of Civil Engineering, Nanyang Institute of Technology, Nanyang 473000, China2. School of Earth Science and Resources, Chang'an University; Key Laboratory of Western China's Mineral Resources and Geological Engineering, Ministry of Education; Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, Ministry of Natural Resources, Xi'an 710054, China3. Key Laboratory of Rare Mineral, Ministry of Natural Resources, Wuhan 430034, China |
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| Abstract: | The East Kunlun Orogenic Belt (EKOB) in the western segment of the Central Orogenic System of China experienced complex and multiple tectono-magmatic events in the past hundreds of millions of years. These tectono-magmatic events from the Late Paleozoic-Early Mesozoic magmatism are most closely related to mineralization. In researching the distribution, evolution and petrogenesis of Late Paleozoic-Early Mesozoic intrusive magmatic rocks as well as geological characteristics of deposits, we investigated the close relationship between tectono-magmatic evolution and mineralization in the eastern part of East Kunlun during this period. Overall, the tectonic evolution of the EKOB can be divided into three stages: the oceanic crust subduction stage (277-240 Ma), syn-collision stage (240-230 Ma) and post-collision stage (230-200 Ma). Crust-mantle magma mixing and mingling occurred during the entire evolutionary process of the Paleo-Tethys Ocean. The mafic plutons are most likely derived from partial co-melting of metasomatic mantle wedge and subduction fluid. Most of the granite magmatites are partial-melting products of the lower crust. The crust-mantle magmatic mixing in the subduction stage of the eastern part of the East Kunlun Orogen brings not only mineralization materials resulting in enrichment of some elements, but also heat source. Physical and chemical deformations of the ore-forming fluid cause mineral precipitation to form a large number of mineral deposits. The main metallogenic combinations are Cu, Mo and Au in small size deposits. In the syn-collision stage, magmatic rock developed rarely due to compressive stress, with ore deposits mainly distributing along the EKOB faults, containing main ore metals Cu, Mo and Au. In the post-collision stage, delamination of lithospheric mantle in an extensional environment provided a channel for mantle materials to participate in mineralization. And the conversion stage from the collision to post-collision stage, specially, is the peak period of Cu, Pb, Zn and Fe metallogenesis from the Late Paleozoic to Early Mesozoic in this area. |
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| Keywords: | East Kunlun Orogenic Belt Late Paleozoic to Early Mesozoic magma evolution magma mixing and mingling mineralization |
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