f Charged Potential Modelling to Design Surveys for Fracture Zone Characterization

Charged potential (CP) survey usually requires high resistivity contrast to produce equipotential area around a conductor, as in theory. Although contrast between fracture zones and highly resistive crystalline bedrock is low, crosshole CP (source at intersection of a borehole and a zone) has been used to characterize fracture zones and to correlate them. If adjacent boreholes are far apart but a zone will outcrop, borehole to surface studies can be applied. However, even minor variation in soil properties can mask the anomalies in potential caused by a weak conductor in bedrock.