The application of shallow seismic and high-density electrical methods in fault zone detectionTaking the western edge fault of the Maoyaba Basin in Litang, western Sichuan as an example

The western margin fault of the Maoyaba Basin, as a branch fault of the Litang Fault Zone in western Sichuan, is the western boundary fault which controls the Great Maoyaba Basin. There have been no reports on its geometric distribution and deep structure. This article uses high-density electrical method and shallow seismic exploration technology to conduct geophysical exploration on the north and south sections of the western edge fault in the Maoyaba Basin, respectively. The response characteristics of the western edge fault in the Maoyaba Basin on high-density electrical method and shallow seismic exploration profiles are analyzed. The western edge fault in the Maoyaba Basin shows lateral displacement of the marker layer on the shallow seismic reflection profile, with the presence of fault diffraction waves and other phenomena. The tomographic inversion velocity profile reflects significant changes in the lateral velocity on both sides of the fault, and it is speculated that the buried depth of the upper breakpoint is shallower than 15m. The low resistance strip characteristics on the apparent resistivity profile inverted by high-density electrical method are preliminarily determined by combining field investigation and regional geological data to determine the production of the fault. Shape, geometric structure, and planar layout. Explored the advantages, disadvantages, and application prerequisites of the two geophysical methods in active fault detection in the article, and combined with similar examples at home and abroad, proposed a combination of multiple methods to more effectively detect fault structures.