转换型微板块类型、成因及其大地构造启示  

Transform-derived Microplates: Classification, Mechanism and Tectonic Significance

作　　者：王光增 李三忠[1,2] 索艳慧 李玺瑶[1,2] 朱俊江 刘永江 郭玲莉[1,2] 刘博 WANG Guangzeng;LI Sanzhong;SUO Yanhui;LI Xiyao;ZHU Junjiang;LIU Yongjiang;GUO Lingli;LIU Bo(Key Lab of Submarine Geosciences and Prospecting Techniques,MOE,Institute for Advanced Ocean Study and College of Marine Geosciences,Ocean University of China,Qingdao 266100,Shandong,China;Laboratory for Marine Geology and Environment,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,Shandong,China)

机构地区：[1]海底科学与探测技术教育部重点实验室,中国海洋大学海洋高等研究院和海洋地球科学学院,山东青岛266100 [2]青岛海洋科学与技术国家实验室海洋地质过程与环境功能实验室,山东青岛266237

出　　处：《大地构造与成矿学》2019年第4期700-714,共15页Geotectonica et Metallogenia

基　　金：“全球变化与海气相互作用”专项(GASI-GEOGE-01);山东省–国家自然科学基金联合基金(U1606401);国家重点研发项目(2016YFC0601002、2017YFC0601401);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);中国博士后科学基金(2017M622274);国家自然科学基金杰出青年基金(41325009);山东省泰山学者特聘教授项目;试采海底孔隙压力监测与海洋物理环境研究(2018c-03-186);青岛市博士后应用研究项目联合资助

摘　　要：大洋或大陆板块由起始到消亡多经历由小变大再由大变小的复杂旋回。微板块作为大洋和大陆板块发育演化的必经阶段,记录了板块格局的变迁历史,可作为研究洋内、陆缘和陆内构造机制的关键对象之一。转换型微板块作为微板块的一种类型,是指主要受大陆或大洋转换断层(或破碎带)所围限和控制形成的微陆块或微洋块。转换型微陆块多发育于洋?陆俯冲系统的大陆一侧,是在大洋板块斜向俯冲背景下通过转换型构造边界从大陆边缘剥离出去的独立块体,空间上常与残生微洋块相伴生。转换型微洋块则发育于大洋转换断层(或破碎带)的转折部位,是洋中脊扩张方向偏转在大洋转换断层内部诱发的新生微洋块。这些微洋块常镜像出现于洋中脊两侧,整体呈平行四边形形态。转换型微板块研究表明转换断层(或破碎带)并非简单的板块转换边界,而是具有一定结构特征的板块生消地带,对其开展研究不仅有利于完善板块生消、旋回、裂解和增生拼贴机理,明确板块发育演化历史,为板块准确重建提供约束,也有助于确定洋中脊?转换断层体系对板块运动方向改变的响应机理和推测未知大洋内的转换断层组合、结构特征及其演化历史,为开拓深海大洋精细化构造研究方向(或“领域”)提供理论依据。The initiation and extinction of oceanic and continental plates often experience a growth cycle from small to large then back to small.As an essential stage of the development and evolution of oceanic and continental plates,microplates inevitably record their deformation and evolution history.Thus,microplates are important in deciphering the deformation mechanism of intra-oceanic,intra-continental and epi-continental structures.As one of the microplate types,transform-derived microplate refers to the continental or oceanic micro-blocks delimited and controlled mainly by continental or oceanic transform faults(or fracture zones).Transform-derived continental micro-blocks are small lithospheric blocks peeled off from the continental margin by strike-slip-dominated tectonic boundary as the oceanic plate subducts obliquely underneath the continental plate.They are often located beside relict oceanic micro-blocks.Transform-derived oceanic micro-blocks are small newborn oceanic lithospheric blocks developed in the bending location of oceanic transform faults(or fracture zones).Such blocks often distribute symmetrically aside the mid-oceanic ridges and comprise a characteristic rhomboidal structure.Their development and evolution are controlled by the arrangement mode and the change of spreading direction of mid-oceanic ridges as they respond to the change of the plate motion direction.Such transform-derived microplates indicate that transform faults(or fracture zones)are not simple plate boundaries,but complex structural belts for plate generation and extinction.Research of transform-derived microplate will help to perfect the initiation,extinction,dissociation,accretion and collage mechanism of the plate,reveal its detailed development and evolution history,and provide constraints for exact plate reconstruction.It may also contribute to the understanding of the response mechanism of mid-oceanic ridge-transform fault system to the change of the plate motion direction,predicting the structure characteristics and evoluti

关 键 词：转换型微板块 大陆转换断层 斜向俯冲 大洋转换断层 洋中脊 扩张方向偏转 

分 类 号：P54[天文地球—构造地质学]