3D inverse modeling of electrical resistivity and induced polarization data versus geostatistical-based modeling

This work aims to compare the 3D geophysical inversion models of electrical resistivity and chargeability with the 3D geostatistical-based models interpolated from 2D inversion of electrical data. The Takht-e-Gonbad Cu deposit situated in the central domain of Iran is chosen to find out the spatial correlation of the porphyry-type ore deposition with the electrical properties. Assuming an ordinary kriging algorithm, the inverted 2D electrical models were interpolated in 3D domain to provide insights about the geometry of Cu-bearing mineralization. Higher values of electrical resistivity and chargeability corresponded to the anomalous zones of Cu mineralization through a fractal analysis of concentration-number (C-N) model derived from exploratory drillings. Surveyed geophysical data were also inverted directly in 3D electrical models to compare them with the geostatistical models, showing that the 3D inversion could much better preserve the geometry of the Cu occurrences, and their classified fractal models were much in close association to each other. The correlation coefficients between the 3D electrical models and the Cu concentration were higher than the geostatistical models, and there is clearly information in the inversion result that is not being captured in the geostatistical interpolation. The significance of this study lies in improvement of the performance of 3D inversion methodology over 3D geostatisitcal interpolation.