Geoelectrical Sounding in Southern Africa using the Cabora Bassa power line with current electrode separations AB up to 1200 km
Values of the apparent resistivity rhoa as a function of the current electrode separation AB/2, together with best fit model curves. The rhoa values marked by + and the dashed first part have been measured by a South African research group (Van Zijl). The model2 interpreted (in red) exhibits a well conducting layer (50 Ω*m) within the high resistive basement at a depth of 24 km with a thickness of 42 km. The equivalent model1, which fits the data equally well, indicates a depth of only 12km.
Source: E.K. BLOHM, P. WORZYK, H. SCRIBA (1977), in Jour.Geophys. 43 (4), pp. 665-679