We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Continent‐Continent Collision Between the South and North China Plates Revealed by Seismic Refraction and Reflection at the Southern Segment of the Tanlu Fault Zone.
- Authors
Li, Haipeng; Li, Junlun; Luo, Song; Bem, Terhemba Shadrach; Yao, Huajian; Huang, Xianliang
- Abstract
The Tanlu Fault Zone (TFZ) is considered as a suture of the intra‐continental collision between the South and North China plates, and it has attracted considerable geological, geochemistry, and geophysical investigations. However, its deep structures still lack clear delineation and the related tectonic processes are still debated without a clear consensus. To better characterize the TFZ as a plate boundary in east China, a 2‐D land seismic survey extending 87 km was conducted across its southern segment to investigate the underlying complex structures. Acoustic full‐waveform inversion (FWI) is applied to the early arrivals of the land seismic data to reconstruct the high‐resolution P‐wave velocity model of the upper crust (above ∼3.5 km). Structures of the crust and the uppermost mantle are further constrained through deep seismic profiling (DSP). The integrated geological interpretation from the FWI and DSP results suggests massive magma upwelling activities, characterized by the reflection‐free zone revealed by DSP and the high‐velocity anomaly recovered by FWI. The TFZ in the study area is found to be a deeply seated fault system with a positive flower structure at its shallow part, which suggests it has undergone a transpression regime. Also, the DSP result provides evidence for the subduction of the South China plate under the North China plate. Finally, a three‐stage model including the compression, transpression, and extension stages is proposed based on the new seismic results to better constrain the tectonic evolution of the southern segment of the TFZ. Plain Language Summary: The Tanlu Fault Zone (TFZ) is a transform fault between the South and North China plates. To better study its tectonic structures, we conducted a 2‐D active‐source seismic survey across its southern segment. We apply the full‐waveform inversion (FWI) method to early arrivals of the acquired data to invert for the P‐wave velocity model along the profile. Furthermore, we apply post‐stack depth migration to image the shallow crust (above ∼3.5 km) and use deep seismic reflections to image structures of the middle and lower crust. A high‐velocity zone in the shallow crust is reconstructed and a weak‐reflection zone is found beneath the TFZ. We suspect these structures are related to the magma intrusion activities. We also found that the southern segment of the TFZ extends deeply through the entire crust and includes multiple branches, assembling a positive flower structure. Besides, from our deep reflection imaging result, it seems that the South China plate subducted under the North China plate. Based on the new findings above, we suggest a three‐stage tectonic model including the plate convergence, the sinistral strike‐slip movement, and the extensional deformation to explain the evolutional history of the study area. Key Points: Full‐waveform inversion is applied to the wide‐aperture land seismic data to reconstruct the P‐wave velocity of the upper crustA deep seismic profiling provides new constraints on the crustal structures at the marginal area between the South and North China platesA three‐stage tectonic model is proposed to explain the tectonic evolution of the southern segment of the Tanlu Fault Zone
- Subjects
CHINA; FAULT zones; SEISMIC migration; VERTICAL seismic profiling; SEISMIC surveys; IMAGING systems in seismology; INVERSION (Geophysics); POSITIVE systems
- Publication
Journal of Geophysical Research. Solid Earth, 2023, Vol 128, Issue 1, p1
- ISSN
2169-9313
- Publication type
Article
- DOI
10.1029/2022JB025748