Induced polarization is an invertible accumulation of charges or their redistribution in the rock under the action of electric current.
Two parameters are measured in the IP method- electric resistivity of rocks (r) and their chargeability – the parameter is used to characterize the formation and strength of the induced polarization within a rock, under the influence of an electric field.
Thus, the main application area of the IP method is prospecting and mapping of disseminated sulfides.
Moreover, the study of either time or frequency (spectral) IP parameters allow one to estimate the textural features of rock which contain electronic minerals. It is also possible to distinguish rocks by the degree of their hydrothermal or metasomatic changes.
The analysis of time and frequency IP parameters sometimes can sufficiently increase the geological interpretation quality of the IP data. Such analysis can even help to obtain the new information regarding the textural features of rocks.
IP measurement technique does not differ great from the DC electro-prospecting (VES, ERT etc.). In the same manner, it requires four electrodes to realize measurements and it can be done in sounding (VES-IP), profiling and tomography (ERT-IP) modes.