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.

Seismic imaging is crucial in investigating Earth’s interior structures and understanding its tectonics and evolution. The reflected, converted, and scattered waves have attracted considerable attention in the previous studies, whereas the directly transmitted waves are less used in seismic imaging. In this study, we present a novel passive source elastic transmitted wave reverse time migration (T-RTM) method to characterize major discontinuities in Earth’s interior using transmitted P or S waveforms. By extrapolating and then cross correlating the wavefields from the sources with the transmitted wavefields from the receivers using flood velocity models, the velocity discontinuities can be clearly imaged. The advantages and potential applications of the proposed T-RTM method are demonstrated with three synthetic imaging experiments. First, with distributed acoustic sensing using submarine cables, we show that the proposed method can be used to image the Moho with teleseismic S waves recorded in a single axial component, which is difficult for other imaging methods. Second, using direct P waveforms with a single P-wave velocity model, we show that the proposed method can be used to image 3D Moho topography without relying on the VP/VS ratio like in the traditional receiver function imaging. Third, the proposed method can also be used to image a fault plane with a sharp velocity contrast using local earthquakes. We discuss the limitations of the proposed method and some potential issues in field-data applications with additional numerical experiments. The proposed T-RTM method could provide many new opportunities for utilizing transmitted waveforms in the study of oceanic and continental structures.