Heterogeneous destruction of the North China Craton： Coupled constraints from seismology and geodynamic numerical modeling

作     者：Kun WANG Liang ZHAO Xiaobing XU Jianfeng YANG 

作者机构：State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institutions of Earth Science Chinese Academy of Sciences Beijing 100029 China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2018年第61卷第5期

页      面：515-526页

核心收录：

学科分类：070801[理学-固体地球物理学] 07[理学] 08[工学] 0708[理学-地球物理学] 080203[工学-机械设计及理论] 0802[工学-机械工程] 0704[理学-天文学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 91414301 & 41604081) 

主　　题：North China Craton Heterogeneity Seismic tomography Numerical modeling 

摘      要：The prevailing academic view regards mantle flow and the metasomatism triggered by the subduction of the Pacific plate as the cause and mechanism for the destruction of the North China Craton(NCC). However, the geodynamic destruction process remains ambiguous, necessitating detailed information at this stage. Combining the structural images obtained by the exploration of dense seismic arrays and the geodynamic simulations inspired by numerical modeling, this paper arrives at the following conclusions: the spatial variation of the P-and S-wave velocities, as well as their velocity ratio in the mantle transition zone, are key evidences of the nonuniform dehydration of the Pacific plate, the subducted plate induces hot upwellings in the mantle transition zone(MTZ), resulting in the heterogeneous distribution of the melt/fluid beneath the craton, characterized by small scale anomalies in the seismic velocity field, and as revealed by dense seismic array observation, the heterogeneities in the upper mantle structure and deformation are the synthetic results of lithospheric strain localization and the heterogeneous distribution of the melt/fluid. It is known that the nonuniform dehydration of the Pacific slab and the heterogeneous distribution of the melt/fluid have occured in the Cenozoic. If these scenarios could have already occurred in the Early Cretaceous, their interaction with the NCC lithosphere would be the dynamic mechanism for the heterogeneous lithospheric destruction of the NCC. The inference in this study is significant for further reconciling the multidisciplinary evidences in the NCC.