Change in the direction of Early Cretaceous tectonic extension in eastern North China Craton as the result of Paleo-Pacific/Eurasian plate interaction  

作　　者：Lei Ji Jun Deng Junlai Liu Xiaoyu Chen Xuefei Liu Xinmin Yang Jinlong Ni Liangliang Zhang Yu An Pengfei Tian 

机构地区：[1]State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China [2]Frontiers Science Center for Deep-time Digital Earth,China University of Geosciences,Beijing 100083,China [3]Shandong University of Science and Technology,Qingdao 266590,China [4]No.1 Exploration Institute of Geology and Mineral Resources of Shandong Province,Ji’nan 250110,China

出　　处：《Geoscience Frontiers》2025年第1期235-248,共14页地学前缘(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos:42130801,41430211,90814006,and 42072226);the“Deep-time Digital Earth”Science and Technology Leading Talents Team Funds for the Central Universities for the Frontiers Science Center for Deep-time Digital Earth,CUGB(Fundamental Research Funds for the Central Universities;Grant No:2652023001).

摘　　要：How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).

关 键 词：Mafic dykes Magnetic fabrics Wulian metamorphic core complex in North China Craton Tectonic extension Subduction of Paleo-Pacific plate 

分 类 号：P54[天文地球—构造地质学]