SOME THEORETICAL ASPECTS OF ELECTRODE POLARIZATION IN ROCKS*

Abstract

AbstractA study has been made on the influence of the several variables of an electrode‐electrolyte system on the different parameters usually measured in connection with the induced polarization method of geophysical exploration. Both the reaction resistance and the Warburg impedance of the system are found to vary appreciably with active ion concentration. The activation energy barrier exerts a predominant influence only on the former, whereas the salt concentration is important to a small degree in the determination of only the latter.With a simple equivalent electrical circuit to represent the complex mechanism of conduction of electrical currents through mineralized rocks, the amplitude and phase of the metal factor are evaluated at a frequency of 10 cps. An analysis is then made to determine the build‐up and decay characteristics of the transient signal in the rock induced by a rectangular current pulse. All these measurable quantities are highly dependent on the salt and active ion concentrations. It is interesting to note that the build‐up or decay time of the transient signal increases normally as the square of the solution resistance and inversely as the square of the Warburg impedance. The activation energy barrier exerts, practically no influence on the metal factor nor on the transient signal.