Mesozoic Thrust-Nappe and Extensional Structure Frameworks in the East Segment of Southeast Yangtze Block, Southeast China  

作　　者：Xinqi Yu Ziwei Chen Jun Hu Yan Zeng Xiu Liu Yu He Zishen Wang Linghui Meng 

机构地区：[1]School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China [2]Chongqing Institute of Geology&Mineral Resources,Chongqing 400042,China

出　　处：《Journal of Earth Science》2020年第4期772-794,共23页地球科学学刊（英文版）

基　　金：supported by the NSFC (No. 41872201)。

摘　　要：Multi-stage Mesozoic thrust-nappe and extensional structures are distributed in the east segment of the Southeast Yangtze Block situated in the junction region of Zhejiang-Jiangxi-Anhui provinces. The features and genetic mechanism of the deformations were analyzed after a detailed field observation of their distribution, geometry, and kinematics. In addition, the time sequences of the thrust and extensional structures were determined by combining the results of the comparative analysis with the chronological evidence of strata and magmatic rocks cut by a fault or formed after a fault according to field facts. This study identified three stages of the nappe structures and at least two stages of the extensional structures during the Mesozoic. The geotectonic setting of the nappe and extensional structures was considered to be related to the different geodynamics in the study area including the Early Mesozoic geological event, i.e., N-S compression, forming Lantian fault, etc.;the Late Mesozoic flat-slab subduction, forming Xiaoxi thrust fault and tectonic window;and the roll-back of the paleoPacific Plate, forming extensional structures like basin marginal fault;the last compression, forming Wucheng-Shenxian fault. These findings provide additional evidence for remodeling the tectonic and geodynamic evolution of Southeast China.

关 键 词：MESOZOIC nappe structure extensional structure time sequence east segment of the Southeast Yangtze Block 

分 类 号：P542[天文地球—构造地质学] P534.5[天文地球—地质学]