A028 1D AND 2D COLE-COLE-INVERSIONS OF TIME DOMAIN INDUCED POLARISATION DATA Summary 1 A new method for the 2D inversion of induced polarization (IP) data in the time domain has been developed. The whole IP transients were observed and inverted into 2D Cole-Cole earth models including resistivity chargeability relaxation time and the frequency constant. First of all a modified time domain electromagnetic algorithm was used to calculate the response of a layered polarizable ground. The transient signals were then inverted using the Marquardt-method to derive the Cole-Cole parameters of each layer. However model calculations showed that the EM effects could