Abstract: The Haizhou-Hanshan fault is an important fault in the Lianyungang area and belongs to the west boundary fault of the Haisi fault zone. It is buried under the shallow cover and controle the boundary of base rock. The shallow seismic reflection method is the preferred method for fault detection, however, by using this method, the detection of the Haizhou-Hanshan fault can only identify the reflected wave on the top surface of the bedrock, and it is difficult to accurately determine the fault. The refraction tomography method is suitable for areas with large lateral velocity differences, and can obtain the difference information of lithologic velocity between two fault plates, then determine fault locations, which can compensate for the lacks in refleetion method. In this paper, shallow seismic reflection and refraction tomography are jointly applied at the same location of the Haizhou-Hanshan fault, and the drill exploration composite geological section and synthetic seismograms are verified. The research shows that the joint application of the two methods can achieve more accurate fault location than the single method, and more abundant fault information, which provides ideas for fault detection under similar geological conditions.

Key words: Fault detection, Shallow seismic reflection, Refraction tomography, Joint application