Shear-wave velocity structures of the shallow crust beneath the Ordos and Sichuan Basins from multi-frequency direct P-wave amplitudes in receiver functions

作     者：Chenxiao TANG Ling CHEN Xu WANG Chenxiao TANG;Ling CHEN;Xu WANG

作者机构：State Key Laboratory of Lithospheric EvolutionInstitute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Deep Earth Science Excellence and Innovation CenterChinese Academy of SciencesGuangzhou 510640China College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China 

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

年 卷 期：2022年第65卷第5期

页      面：810-823页

核心收录：

学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 41688103 and 42004041) 

主　　题：Shallow crustal velocity structures Receiver function Frequency dependence Ordos Basin Sichuan Basin Tectonic evolution 

摘      要：As the two largest cratonic basins in China,the Ordos Basin and the Sichuan Basin are of key importance for understanding the evolutionary history of the Chinese *** this study,the shear-wave velocity(V_(S))structures of the shallow crust(depth up to 10 km)beneath the two basins are imaged based on the frequency-dependence of direct P-wave amplitudes in receiver *** teleseismic data used in the study came from 160 broadband seismic stations,including permanent and temporary *** results show that the V_(S) and the thickness of the sediments in the Ordos Basin and the Sichuan Basin are respectively lower and thicker in the west than in the *** the Ordos Basin,the shallow crustal V_(S) increases gradually from 2.10 km s^(−1)in the northwest to 2.65 km s^(−1)in the southeast and the thickest sediments are 7–8 km in the northwest and 5 km in the *** the Sichuan Basin,the shallow crustal V_(S) increases from 2.4 km s^(−1) in the west to 2.7 km s^(−1)in the east and the thickness of the sediments decreases from7 km in the west to 6 km in the *** east-west difference of the shallow crustal structures of the two basins may have been controlled by the Cenozoic India-Eurasia *** western parts of the basins near the collision have a higher deposition rate,while in the parts inside the basins far from the collision,the V_(S) slowly increases with depth,indicating that these areas have experienced a more uniform deposition *** addition,both basins are characterized by velocity structures that are higher along the edges and lower inside of the *** edges of the basins suffered strong denudation due to the uplifting and deformation influenced by tectonic *** downward gradient of the shear-wave velocity beneath the Ordos Basin is twice that of the Sichuan Basin,which may be caused by the different deposition and denudation rates of the two basins resulting from differences in structural evolution and thermal