Geochemical evolution of Mesozoic and Cenozoic mafic igneous rocks in the eastern Tethyan realm:Implications for the tectonic evolution of convergent plate margins  

作　　者：Long CHEN YongFei ZHENG 

机构地区：[1]Frontiers Science Center for Deep Ocean Multispheres and Earth System,Key Lab of Submarine GeoSciences and Prospecting Techniques,MOE and College of Marine GeoSciences,Ocean University of China,Qingdao,266100,China [2]Laoshan Laboratory,Qingdao,266237,China [3]State Key Laboratory of Lithospheric and Environmental Coevolution,School of Earth and Space Sciences,University of Science and Technology of China,Hefei,230026,China

出　　处：《Science China Earth Sciences》2025年第4期1116-1141,共26页中国科学(地球科学英文版)

基　　金：financially supported by the National Natural Science Foundation of China(Grant Nos.92155306,42072061,92058211);the Shandong Excellent Young Scientist Grant(Grant No.ZR2022YQ32)。

摘　　要：The convergent plate margins of Paleo-Tethys Ocean and Neo-Tethys Ocean are the two orogenic belts in the eastern Tethyan realm with the best exposures of igneous rocks.Previous studies have revealed that both belts have developed not only island arc basalts(IAB)-like mafic magmatism but also ocean island basalts(OIB)±mid-ocean ridge basalts(MORB)-like mafic magmatism in various stages of their formation and evolution.These different types of mafic igneous rocks show both similarity and difference that were acquired in the various stages from oceanic subduction through continental collision to intracontinental reworking.Comprehensive examination and comparison of these igneous rocks can provide insights into the tectonic evolution of the eastern Tethyan realm.This study integrates the spatiotemporal distribution and geochemical compositions of Mesozoic and Cenozoic primitive mafic igneous rocks in the eastern Tethyan realm within China.The results show:(1)in addition to the stage of oceanic subduction,the stages of continental collision and intracontinental reworking are the primary periods of mafic magmatic activity at convergent plate margins,consistent across the Paleo-Tethyan and Neo-Tethyan domains.(2)OIB(±MORB)-like mafic igneous rocks are present not only in the stage of continental collision in both domains but also in the stage of intracontinental reworking in the Paleo-Tethyan domain.(3)In the stages from oceanic subduction to continental collision,the compositions of IAB-like mafic igneous rocks in both domains exhibit continuous variations,with remarkable similarities in lithology,elemental and isotopic characteristics,indicating their formation through similar deep geodynamic processes—partial melting of the mantle wedge metasomatized by subducting slab-derived fluids in the forms of aqueous solution and/or hydrous melts.As a consequence,the mafic igneous rocks display more compositional inheritance than difference.In the stage of continental collision,the mantle sources of mafic igneous rocks di

关 键 词：Convergent plate margin Oceanic subduction Continental collision Intracontinental reworking Mafic magma-tism Crust-mantle interaction 

分 类 号：P588.1[天文地球—岩石学]