Crustal deformation in the vicinity of the Tan-Lu Fault Zone in East China constrained by receiver function analyses

• Published in: Tectonophysics Vol. 876; p. 230265
• Main Authors: Zheng, Tuo, Wang, JiaXuan, Gao, Stephen S., Ding, Zhifeng, Liu, Kelly H., Yu, Youqiang, Gu, Qinping, Fan, Xiaoping, Chang, Lijun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.04.2024
• Subjects: Crustal anisotropy; Crustal deformation; Receiver function; Tan-Lu Fault Zone; Crustal anisotropy; Crustal deformation; Tan-Lu Fault Zone; Receiver function
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2024.230265

To investigate the spatial distribution of crustal deformation and related geodynamic processes associated with the Tan-Lu Fault Zone (TLFZ) in East China, we measured crustal anisotropy based on the sinusoidal moveout of the P-to-S conversions from the Moho observed on receiver functions. Totally 142 well-defined crustal anisotropy measurements were obtained from the China National Seismic Network and other broadband dense seismic stations, including three stations exhibiting the pattern of a double layered anisotropy structure. The fast orientations observed at stations in the vicinity of the TLFZ were dominantly fault-parallel except for the southernmost part of the study area, where the fast orientations were approximately normal to the strike of the fault zone and may primarily be attributed to the NW-SE oriented Dabie Orogenic Belt. In the North China Block, NW-SE fast orientations were found to be consistent with the dominant orientation of the secondary faults. The Lower Yangtze Block showed two dominant fast orientations. The fault-parallel measurements in the west of the Jiangshao Fault Zone were controlled by the NE-trending faults in the Lower Yangtze Block, while the fast orientations in the east and south of the Jiangshao Fault Zone were dominantly E-W, which could be mainly influenced by the regional principal compressive stress. The average delay time of the entire study area was 0.27 ± 0.07 s. In the vicinity of the TLFZ where fault-parallel fast orientations were observed, an approximately 44% increase in delay time was observed, suggesting a well-developed fault zone. •Crustal anisotropy is measured at 142 stations from the provincial seismic networks and dense temporary seismic stations.•Reverberation removal on receiver functions leads to more reliably defined results.•Significant anisotropy in the Tan-Lu Fault Zone is closely related to the degree of crustal deformation.•Contrasting anisotropy measurements are observed in the Lower Yangtze Block.