Geoelectric interpretation of petrophysical and hydrogeological parameters in reclaimed mine tailings areas

The research applies non-invasive electrical resistivity imaging (ERI) for the quantitative interpretation of electric and hydrogeological parameters in a reclaimed tailings area. Composition, porous structure and clay content do not change significantly in the tailings matrix but have influence in bulk electrical resistivity. Therefore, the tailings matrix was included in a multiphase approach known as generalized Archie's equation and modelled for interpretation of bulk electrical resistivity, water content and saturation in the vadose zone of the waste deposit. The results are consistent to explain the sensitivity of electrical resistivity to tailings hydrogeological parameters. The model provides a reliable approximation of the distribution of water content and saturation in the vadose zone and describes quantitatively for the first time the role of the tailings matrix as contributor of the electrical response. It also confirms that pore-water of ionic composition and saturation are the controlling factors for the variability of the bulk electrical resistivity. The method described in the paper is beneficial for predicting electrical and hydraulic parameters in tailings facilities, which is important for monitoring the integrity of these structures into the future.