Key geodynamic processes and driving forces of Tethyan evolution  

作　　者：Zhong-Hai LI Fengyuan CUI Shuting YANG Xinyi ZHONG 

机构地区：[1]Key Laboratory of Computational Geodynamics,College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Earth Sciences》2023年第12期2666-2685,共20页中国科学（地球科学英文版）

基　　金：a review of the geodynamic studies and extended thoughts during the past four years (2019–2022)in the platform of“Major Research Plan on Tethys Geodynamic System”funded by the National Natural Science Foundation of China (Grant No.91855208);supported by the National Natural Science Fundation of China for Distinguished Young Scholars (Grant No.42225403)。

摘　　要：Tethys tectonic system has experienced a long-term evolution history,including multiple Wilson cycles;thus,it is an ideal target for analyzing plate tectonics and geodynamics.Tethyan evolution is typically characterized by a series of continental blocks that separated from the Gondwana in the Southern Hemisphere,drifted northward,and collided and accreted with Laurasia in the Northern Hemisphere.During this process,the successive opening and closing of multistage Tethys oceans(e.g.,Proto-Tethys,Paleo-Tethys,and Neo-Tethys)are considered core parts of the Tethyan evolution.Herein,focusing on the life cycle of an oceanic plate,four key geodynamic processes during the Tethyan evolution,namely,continental margin breakup,subduction initiation(SI),Mid-Ocean Ridge(MOR)subduction,and continental collision,were highlighted and dynamically analyzed to gather the following insights.(1)Breakup of the narrow continental margin terranes from the northern Gondwana is probably controlled by plate subduction,particularly the subduction-induced far-field stretching.The breakup of the Indian continent and the subsequent spreading of the Indian Ocean can be attributed to the interactions between multiple mantle plumes and slab drag-induced far-field stretching.(2)Continental margin terrane collision-induced subduction transference/jump is a key factor in progressive Tethyan evolution,which is driven by the combined forces of collision-induced reverse push,far-field ridge push,and mantle flow traction.Moreover,lithospheric weakening plays an important role in the occurrence of SI.(3)MOR subduction is generally accompanied by slab break-off.In case of the considerably reduced or temporary absence of slab pull,mantle flow traction may contribute to the progression of plate subduction.MOR subduction can dynamically influence the overriding and downgoing plates by producing important and diagnostic geological records.(4)The large gravitational potential energy of the Tibetan Plateau indicates that the long-lasting India-Asia continental

关 键 词：Continental margin breakup Subduction initiation Mid-Ocean Ridge subduction Continental collision Tethys geodynamics 

分 类 号：P541[天文地球—构造地质学]