Application of transient electromagnetic method in the detection of water-bearing fault structure

In areas covered by thick loess and looses sand, 3D seismic is inefficient in detecting fault structure. In view of this situation, an engineering try by using TEM method to detect the fault structure was done in Youyu mine. The grid is 40 m × 20 m and the exploration area is 2.5 km². The preliminary test result of the area with known fault structures indicates that the fault structure where the up and down sides have electrical difference or are filled with water shows bending-down contour and electrical layer dislocation of electric layer in apparent resistivity section; the contours of fault with different drop bend in different degree, the contours bend more greatly if the drop is bigger. Based on this, 49 faults are interpreted in the exploration area. At present, 5 faults have been proved during the roadway excavation and the revealed result is coincident with interpretation, so effectiveness of the method gets verified.