摘要
班公湖?怒江洋多岛弧盆体系的俯冲闭合过程对于研究青藏高原早期形成与演化具有重要意义。本文系统总结了羌南?保山地块与拉萨地块燕山期的岩浆岩、沉积序列以及变质变形特征,详细探讨了其与班公湖?怒江洋俯冲闭合过程的联系。研究结果显示随着特提斯大洋的打开,羌南?保山地块、拉萨地块、聂荣微地块和嘉玉桥微地块均作为裂生微地块从冈瓦纳大陆北缘裂解出来,北拉萨地块是班公湖?怒江洋南向俯冲弧后扩张裂解的产物,并随着大洋的南向俯冲,逐渐演变为增生型微地块。随着洋盆的闭合这些微地块作为残生微地块碰撞拼贴在一起,保留在造山带之中。班公湖?怒江洋在燕山期经历了复杂而漫长的多个微小地块的碰撞增生过程。该过程最早可能始于晚侏罗世,并主体于早白垩世末期?晚白垩世初期汇聚消亡,期间经历了纵向和横向的双重穿时性。印度?雅鲁藏布江洋的北向俯冲作用对于班公湖?怒江洋的汇聚消亡以及青藏高原现今主体构造格架形成至关重要。
The subduction and closure of the Bangong-Nujiang Ocean are recognized as significant events in the geotectonic evolution of Tibetan Plateau.This study focuses on the Mesozoic magmatic rocks,sedimentary strata,metamorphic and deformation features,and discusses their relation with the evolution of the Bangong-Nujiang Ocean in details.The Qiangnan-Baoshan,Lhasa,Nierong and Jiayuqiao micro-blocks rifted from the northern margin of the Gondwana as rifting-induced micro-blocks.The northern Lhasa micro-blocks was a product of the back-arc spreading of the Bangong-Nujiang Ocean,and evolved into an accretion-induced micro-blocks due to the southward subduction of the Bangong-Nujiang Ocean.All these micro-blocks collaged together as subduction-derived micro-blocks preserving in the orogenic belt.The Bangong-Nujiang Ocean experienced a complex and prolonged process of multiple collage and collision among micro-blocks during the Mesozoic period.This process may have started in the Late Jurassic and completed at the end of the Early Cretaceous to early Late Cretaceous.Both longitudinal and transverse diachronism occurred during the closure of the Bangong-Nujiang Ocean.The northward subduction of the Indus-Yarlung Zangbo Ocean is important to the closure of the Bangong-Nujiang Ocean,as well as the formation of the modern tectonic framework of Tibetan Plateau.
作者
刘一鸣
李三忠
于胜尧
曹现志
周洁
李阳
王誉桦
徐林山
郭润华
周在征
LIU Yiming;LI Sanzhong;YU Shengyao;CAO Xianzhi;ZHOU Jie;LI Yang;WANG Yuhua;XU Linshan;GUO Runhua;ZHOU Zaizheng(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 Mineral Resources,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,Shandong,China;Beijing Institute of Geological Engineering,Beijing 100050,China)
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2019年第4期824-838,共15页
Geotectonica et Metallogenia
基金
国家重点研发计划项目(2017YFC0601401)
博士后创新人才支持计划项目(BX201700216)
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项目(2017M622273)
国家自然科学基金项目(41802232、41702050、41325009)
青岛市博士后应用研究项目联合资助
