Crustal structure and deformation of the SE China revealed by Receiver Functions
会议日期：2021年
学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学]
关 键 词：Crustal structure and deformation of the SE China revealed by Receiver Functions
摘 要：Due to the subduction of the Paleo-Pacific and Philippine plates, a large-scale magmatism and crustal thinning are generated beneath the Southeastern(SE) China. However, the nature of deformation at depth in this region is still not well understood. In this study, a large numbers of receiver functions were used to investigate the crustal thickness, Vp/Vs ratio and seismic anisotropy beneath the SE China using the H-κ stacking technique and a comprehensive splitting measurement technique. The measured results show that a significant high Vp/Vs ratio(～1.85) mainly spread around two areas, which formed two branches. The western branch was the North-South trend with a thin crustal thickness ～29.1 km beneath Nanxiang-Jianghan basin, the eastern branch extended along the Tanlu fault with a thin crustal thickness ～28.8 km. These two-branch significant thin crustal thickness zones are consistent with the V-shaped crustal thinning zone. Moreover, the measured seismic anisotropy results show that most of the seismic stations located near the V-shaped crustal thinning zone exhibit significant seismic anisotropy with the splitting time of 0.20-0.72 s and the fast directions are parallel to the branches of the V-shape. Combining the geological data and the tectonic background, we propose that the hot fingers may grow from the mantle corner flow in the southern part of our V-shape zone associated with the collision of the Philippine plate and the eastward high angle subduction of the Eurasian plate. We also deduce that this mantle corner flow might generate the V-shaped crustal thinning and cause the Moho uplift in the SE China.