f A New FD Method for 3D Resistivity Modelling with Application to a Phonolithic Body

With increasing computer capacity, 3D resistivity modeling is becoming realistic for routine application where necessary. The presentation focuses on two topics: First on a 3D finite difference (FD) algorithm for DC resistivity modeling which has recently been developed at the Geological Survey of Lower Saxony in Hannover, and second on its application to field data obtained through the Applied Geophysics Section of the University of Bonn. The object of the field study was an outcropping, highly resistive phonolithic body at Sainerholz/Westerwald in Germany. Conventional 1D and 2D interpretations failed to produce satisfying results. The vertical electrical soundings (VES) can, however, be approximated by the computed response of a 3D resistivity structure consistent with other geophysical data.