摘要
任何板块都存在一个由小长大的过程。微地块(微板块)有时是大板块的前身,微地块的起源、生长、夭折、消亡和残留过程对研究板块构造具有重要意义。据其组成,微地块可划分为微陆块、微洋块、微幔块。本文以太平洋、印度洋和大西洋中的微地块为例,系统总结了洋脊增生系统、俯冲消减系统、深海板内系统、伸展裂解系统、碰撞造山系统5种构造环境下的微地块特征,并据此首次进行了成因分类,提出拆离微地块、裂生微地块、转换微地块、延生微地块、跃生微地块、残生微地块、增生微地块、碰生微地块和拆沉微幔块9种类型。对不同类型微地块边界进行了系统界定,并对其成因进行了系统讨论。这些微地块边界类型,包括活动的或死亡的拆离断层、俯冲带、洋中脊、转换断层、破碎带、切割岩石圈的断裂、假断层、洋内汇聚带、叠接扩张中心、非叠接扩张中心、洋脊断错等,其成因的关键研究在于对三节点稳定性进行分析。洋内或洋缘微地块研究,不仅为开展深海大洋精细化构造分析和板块重建工作提供参考,而且对解释大陆内部一些微地块成因具有启发性,可丰富大陆造山带、陆内、板内、幔内和陆缘构造的研究内容,使得造山带演化、板内变形和地幔过程研究更为精细化,甚至推广到早前寒武纪的前板块构造机制研究。
Any plate has a growth process from small to large.Microblocks or microplates are sometimes the precursors of large plates.The origin,growth,aborting,extinction and residual processes of microblocks are of great significance for the study of plate tectonics.Microblock can be classified as micro-continental,micro-oceanic and micro-mantle block according to its composition.In this paper,the characteristics of microblocks in the Pacific,Indian and Atlantic oceans are summarized according to five environments of the mid-ocean ridge,subduction system,deep-sea intraplate,extensional rifting and collisional orogenic systems.We first propose a genetic classification of micro-blocks as the detachment-,rifting-,transform-,propagation-,ridge jumping-,subduction-,accretion-,collision-and delamination-induced micro-mantle blocks.We then discuss the different types of micro-block boundaries systematically.These micro-block boundaries include active or inactive detachment fault,subduction zone,mid-ocean ridge,transform fault,fracture zone,lithosphere-scale fault,pseudo-fault,intra-oceanic collisional zone,overlapping spreading center,non-transform offset,ridge offset and others.The key research of boundary formation is the stability analysis of triple junctions.These microblocks,within the oceanic basin or along the oceanic margin,are significant not only for developing deep ocean fine structural analysis and plate reconstruction,but also for explaining the causes of microblocks in orogens,intra-continent,intra-ocean,intra-mantle and continental margins to improve research precision towards a more detailed understanding of orogenic belt evolution,intraplate deformation and mantle processes,or even extending our study into the early Precambrian pre-plate tectonic mechanisms.
作者
李三忠
索艳慧
刘博
刘永江
李玺瑶
赵淑娟
朱俊江
王光增
张国伟
LI Sanzhong;SUO Yanhui;LIU Bo;LIU Yongjiang;LI Xiyao;ZHAO Shujuan;ZHU Junjiang;WANG Guangzeng;ZHANG Guowei(Key Laboratory 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)
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2018年第5期324-355,共32页
Earth Science Frontiers
基金
青岛海洋科学与技术国家实验室鳌山科技创新计划项目(2016ASKJ13
2017ASKJ02)
国家自然科学基金杰出青年基金项目(41325009)
山东省泰山学者特聘教授项目资助
关键词
微地块
微板块
板内
陆缘
洋中脊
俯冲带
前寒武纪
micro-block
microplate
intraplate
continental margin
mid-ocean ridge
subduction zone
Precambrian
