地学前缘 ›› 2018, Vol. 25 ›› Issue (6): 67-77.DOI: 10.13745/j.esf.sf.2018.11.11

• 岩石探针与全球构造 • 上一篇    下一篇

大陆边缘弧岩浆成因与大陆地壳形成

朱弟成,王青,赵志丹,牛耀龄,侯增谦,潘桂棠,莫宣学   

  1. 1. 中国地质大学 地质过程与矿产资源国家重点实验室; 中国地质大学(北京)科学研究院, 北京 100083 
    2. 中国科学院 青藏高原地球科学卓越研究中心, 北京 100101
    3. Department of Earth Sciences, Durham University, Durham DH1 3LE, UK 
    4. 中国地质科学院 地质研究所, 北京 100029 5. 成都地质矿产研究所, 四川 成都 610059
  • 收稿日期:2018-10-30 修回日期:2018-11-10 出版日期:2018-11-30 发布日期:2018-11-30
  • 作者简介:朱弟成(1972—),男,教授,博士,主要从事岩浆作用与青藏高原形成和特提斯演化研究。E-mail:dchengzhu@163.com
  • 基金资助:
    国家自然科学基金委员会“特提斯地球动力系统”重大研究计划重点支持项目(91755207);国家重点研发计划项目(2016YFC0600304);教育部、国家外国专家局高等学校学科创新引智基地项目(B18048)

Magmatic origin of continental arcs and continental crust formation.

ZHU Dicheng,WANG Qing,ZHAO Zhidan,NIU Yaoling,HOU Zengqian,PAN Guitang,MO Xuanxue   

  1. 1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences; Institute of Earth Sciences, China University of Geosciences(Beijing), Beijing 100083, China
     2. CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China 
    3. Department of Earth Sciences, Durham University, Durham DH1 3LE, UK 
    4. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 
    5. Chengdu Institute of Geology and Mineral Resources, Chengdu 610081, China
  • Received:2018-10-30 Revised:2018-11-10 Online:2018-11-30 Published:2018-11-30
  • Supported by:
     

摘要: 大陆地壳如何形成是国际学术界长期关注并正在持续攻关的一个重大基础科学问题。活动陆缘弧的岩浆成因和密度分选过程是理解大陆地壳形成机制和演化过程的关键。北美白垩纪Cordilleran大陆边缘弧的形成可能经历了与底侵幔源岩浆有关的下地壳部分熔融和岩浆混合,或幔源初始玄武质岩浆的两阶段成分分异过程,以花岗质成分为主的北美内华达地区垂向地壳成分剖面结构可能与榴辉岩相残留体或堆晶岩的拆沉作用密切相关。目前并不清楚亚洲大陆南部以约200 Ma和约90 Ma两个时间断面为代表的中生代冈底斯弧,为何出现大量角闪石岩并具有玄武安山质的平均成分。探究中生代冈底斯弧的岩浆成因、地壳垂向成分结构和地壳形成机制可能有助于或多或少地解决这一问题。

 

关键词: 地壳形成, 中生代冈底斯弧, 白垩纪Cordilleran弧, 青藏高原南部, 北美

Abstract: How the continental crust is formed has long been a fundamental scientific question for the international academic community. Magmatic origin and density filtering of arcs at active continental margins are crucial to understanding formation and evolution of continental crust. The Cretaceous Cordilleran continental margin arc in North America may have formed through partial melting of lower crust and magma mixing associated with mantle-derived magmatic underplating, or two-stage compositional differentiation of mantle-derived initial basaltic magma. The vertical crustal compositional section that is dominantly granitic in the Nevada region of North America is most likely related to the delamination of eclogite facies residues or cumulates. It is currently not clear that why the Mesozoic Gangdese arc in southern Tibet is characterized by the occurrence of a large amount of hornblendites and the presence of an arc crust with basaltic andesitic composition in average at ca. 200 Ma and ca. 90 Ma. This problem may be resolved more or less by exploring the magmatic origin, vertical crustal compositional profile, and crustal formation mechanism of the Mesozoic Gangdese arc.

Key words: crustal formation, Mesozoic Gangdese arc, Cretaceous Cordilleran arc, southern Tibet, North America

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