Modeling electrical dispersion phenomena in Earth materials

Abstract

It is illustrated that IP phenomena in rocks can be described using conductivity dispersion models deduced as
solutions to a 2nd-order linear differential equation describing the motion of a charged particle immersed in an
external electrical field. Five dispersion laws are discussed, namely: the non-resonant positive IP model, which
leads to the classical Debye-type dispersion law and by extension to the Cole-Cole model, largely used in current
practice; the non-resonant negative IP model, which allows negative chargeability values, known in metals
at high frequencies, to be explained as an intrinsic physical property of earth materials in specific field cases; the
resonant flat, positive or negative IP models, which can explain the presence of peak effects at specific frequencies
superimposed on flat, positive or negative dispersion spectra.