摘要
The shallow low resistivity layer has a shielding effect on the detection signal of the transient electromagnetic method;in areas with thick low resistivity overburden,in particular,the completion of exploration task at great depth must be based on the choice of proper technology during the construction and interpretation.In thick low resistance covering layer of North China,the authors conducted the transient electromagnetic exploration and the tests on the construction techniques and data interpretation.It is considered that during the field work,we must select the appropriate loop size and sampling time,use launch power as large as possible to produce a higher signal-to-noise ratio,and that during data analysis and interpretation,MT inversion should be used for prominence of the anomaly.In the low resistance layer with thickness up to 300 m,the authors completed the locating and detection of the water-rich area at the depth of 550 m,and the rich water resources were proved by drilling.The results show that the methods can be used in the low resistance layer water detection in the area affected by low-resistivity overburden.