Resolution of deep structures for DC resistivity method:2D inversion for 3D model

Numerical simutation for 3D model with deep structures was carried out by using 3D finite difference resistivity modeling method.2D inversion of calculated apparent resistivity profiles of pole-pole and symmetric four-pole sounding was studied.The result indicates that pole-pole system can resolve 3D structures if the hori-zontal interval of the center of 3D abnormal bodies is not less than the total depth of the center of the two structures.Under the same conditions,symmetric four-pole system has horizontal resolution better than pole-pole system,and pole-pole system has vertical resotution better than symmetric four-pole system.