摘要
中生代期间,华北与华南地块受西太平洋的板块俯冲过程、东亚大陆边缘深浅部过程的影响,其构造、岩浆、成矿、地貌演化趋势表现出一些共性,但也存在显著差异,其动力机制一般认为由古太平洋板块俯冲所致,但是它们是如何关联的,长期未得到解决,是地质研究的难点和热点,存在巨大争论.本文系统评述了近十年来已有东亚大陆边缘的构造变形分析、岩浆岩年代学、层析成像等多学科成就,简要探讨了前燕山期的中国陆块的最终聚合、统一陆缘的形成,随后主要侧重综述侏罗纪、白垩纪东亚洋陆过渡带燕山期地质过程的新认识.本文将浅部构造变形规律、岩浆岩年龄分带和迁移、地形巨大反转,与深部过程紧密结合,提出:华北克拉通破坏过程总体受深部岩石圈早幕向西的分层回卷拆沉、减薄制约,导致早期构造、岩浆作用伴随西迁,中幕多向拆沉,晚幕拆沉向东回撤;同时,北部鄂霍茨克洋闭合与南部班公湖-怒江俯冲系统的同期联合作用使得东亚洋陆过渡带总体处于挤压背景下,且深部上涌的软流圈不断向东跃迁,带动岩石圈不断向东、幕式、交替性伸展和挤压.华南深部早期则经历了向西平板俯冲,导致变形和岩浆作用西迁;后期发生两幕拆沉,导致构造-岩浆作用向东跃迁.总之,华北与华南构造-岩浆差异的内因是深部过程,外因是东亚大汇聚的差异所致.
The Mesozoic impact to the North China and the South China blocks in the East Asian Continental Margin by the West Pacific subduction processes and deep processes, the tectonic, magmatic mineralization and geomorphic evolutionary trends show some similarities, but there are also significant differences beween them, the dynamic mechanism is generally believed to be caused by the Paleo-Pacific Plate subduction. But how they are related is a long-term unresolved question as a conundrum and a focus of geological researches, and a huge controversy is still remained. This paper systematically summarizes the comprehensive achievements of deformation analysis, igneous geochronology, tomography and other field observations in the East Asian Continental Margin in recent decade, briefly discussing the pre-Yanshanian final assembly of blocks and the formation of the unified continental margin in China, and mainly focusing on the review of Jurassic and Cretaceous geological processes in the East Asian Ocean-Continent Connection Zone in the Yanshanian period. The temporal and spatial evolution of structural propagation, age zonation and migration of igneous rocks and huge tectono-morphological inversion in the Earth surface system, combined with deep processes are jointly to put forward： the destruction of the North China Craton was mainly affected by the westard early-stage layerred rollback, delamination and thinning of the deep lithosphere, resulting in early Yanshanian westward migration of tectonism and magmatism following the middle-stage multiple-directional delamination and the late-stage eastward withdrawal of delamination; coevally, the combined effect of the closure of the Okhotsk Ocean to the north and the subduction of the Bangong-Co-Nujiang Ocean to the south made the East Asian Ocean-Continent Connection Zone under the tectonic setting of overall compression, the asthenosphere upwelling at depth continued an eastward migration to drive lithosphere continuously eastward and periodical, alternative extension and compression. The South China Block experienced the westward flat subduction at early stage, resulting in the westward propagation of deformation and magmatism, following the late two-stage delamination to induce the eastward tectono-magmatism. In summary, the tectono-magmatic differences between the North China and South China blocks are caused by their difference of the deep mantle processes and the East Asian plate superconvergence.
作者
李三忠
索艳慧
李玺瑶
王永明
曹现志
王鹏程
郭玲莉
于胜尧
兰浩圆
李少俊
赵淑娟
周在征
张臻
张国伟
Sanzhong Li;Yanhui Suo;Xiyao Li;Yongming Wang;Xianzhi Cao;Pengcheng Wang;Lingli Guo;Shengyao Yu;Haoyuan Lan;Shaojun Li;Shujuan Zhao;Zaizheng Zhou;Zhen Zhang;Guowei Zhang(Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China;Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China;Department of Geology, Northwest University, Xi＇an 710069, China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2018年第16期1550-1593,共44页
Chinese Science Bulletin
基金
国家重点研发计划(2017YFC0601401)
国家海洋局“全球变化与海气相互作用”专项(GASI-GEOGE-1)
山东省“泰山学者”特聘教授计划
青岛海洋科学与技术国家实验室“鳌山人才卓越科学家”计划(2015ASTP-0S10)
国家自然科学基金委-山东省联合基金(U1606401)资助
关键词
洋陆过渡带
古太平洋板块
东亚
燕山期
大陆边缘
俯冲后撤
ocean-continent connection zone
Paleo-Pacific Plate
East Asia
Yanshanian
continental margin
subduction retreat
作者简介
李三忠,E-mail:sanzhong@ouc.edu.cn
