On rule of thumb interpretation of restivity gradient array data

Abstract

The so called resistivity gradient array, described by Whiteley (1973) and illustrated in figure 1, presents a unique opportunity for the application of semi-quantitative interpretation techniques based on potential theory. Large current electrode separations, as encountered in the resistivity gradient array, enable the applied potential field in the vicinity of the centre of the array to be closely approximated by a constant field (Kunetz, 1966). The assumption of a constant applied field considerably reduces the complexity of mathematical treatment.