Detection of the Late Quaternary activity of the Liaocheng-Lankao Fault in the south-central part of the North China Plain: Discussion on the seismogenic mechanism of the 1937 Heze M 7.0 earthquake

Objective The North China Plain (NCP) is one of the most populated and economically developed areas in China and is a region with a high level of seismic hazards. Studying the Quaternary activity of the faults and the seismogenic mechanism of the large earthquakes in NCP is conducive to exploring the seismogenic pattern of intraplate earthquakes and reducing the damage caused by seismic hazards. The Liaocheng-Lankao fault (LLF) is an important buried deep major fault in the south-central part of the NCP. The activity of the LLF and its relationship with the 1937 Heze M 7.0 earthquake is still highly controversial. Methods In this study, the activity of the Liaocheng-Liaokao fault is finely studied by combining shallow seismic exploration, drilling, and Quaternary dating methods. Results Shallow seismic reflection profile ZF-2 reveals that the strata below 145 m are obviously displaced, and the strata above 145 m are disturbed. The Bachengsi drilling profile reveals 16 sets of marker layers and three west