Electrical Resistivity Tomography Applied at Different Stages of Gypsum Exploitation

Abstract

During the extraction of the rock in gypsum quarries, one of the most important parameter is the compositional changes in the deposit. Sudden changes in the purity makes the processing of the raw material less profitable. A resistivity survey has been carried out in an active gypsum quarry in the Gelsa Gypsum unit (Zaragoza, N Spain). The performed electrical resistivity tomography profiles have shown different gypsum layers from which the purest layers have been identified. These variations are displayed as changes in the conductivity of the rocks due to the presence of matrix. Additionally to the quarry front profiles, the quality of the gypsum deposits of a nearby area has been studied by parallel lines in order to evaluate the possibility of future exploitation. Additionally to the geophysical survey, the different gypsum levels of the quarry have been sampled in order to characterize them mineralogycally. With all this information, the planning of the present and future works can be improved.