Integrated Interpretation of Electrical Resistivity Tomography for Evaporite Rock Exploration: A Case Study of the Messinian Gypsum in the Sorbas Basin (Almería, Spain) Pérez López, Alberto Diego García-López, Miguel González-Gil, Miguel Selenite Alabastrine Anhydrite Sorbas basin SE Iberia Electrical tomography Seismic Geophysical prospecting Acknowledgments: The authors would like to express their thanks to Saint-Gobain Placo Iberica, S.A., for the information and data of the study area provided for the realization of this work. Thanks are also due to the company’s personnel for the facilities provided to carry out the work, and thanks to the three anonymous reviewers for their helpful and constructive reviews of the manuscript. In this study, we conduct an investigation of the Sorbas Basin (Almería, Spain) on the Messinian gypsum unit using geophysical prospecting methods. Geophysical electrical resistivity tomography (ERT) methods were applied to study the subsurface of this gypsum unit, the exploitation of which could be of interest economically, with different commercial specifications for alabastrine and selenitic gypsums. For the interpretation of the different ERT images, the data for the surface geology, borehole cores, and seismic refraction conducted at a point within the ERT profiles were used. The results obtained from this investigation can be used as a reference for other similar studies in other regions. It was observed that selenitic gypsum is more resistive than alabastrine gypsum; therefore, the diagenetic processes of dehydration (anhydritization) and hydration (gypsification) increase the “percolation” phenomenon through possibly ensuring a greater connectivity of the shale matrix. Fracturing and moisture can be used to fully determine the resistivity of the purest and most resistive gypsum, to the point of considerably lowering the resistivity in an entire area affected by fracturing. The use of different tests with different lengths for the same profile can help one better understand the structure of the gypsum body in the subsurface, especially when there are shale intercalations or more- or less-pure levels of gypsum that do not reach a value of a few meters in thickness, because these thinner levels of a few meters are not defined in the ERT images when the test is performed at depths of up to 75 m. 2023-04-19T09:58:10Z 2023-04-19T09:58:10Z 2023-01-17 info:eu-repo/semantics/article Pérez-López, A.; García- López, M.; González-Gil, M. Integrated Interpretation of Electrical Resistivity Tomography for Evaporite Rock Exploration: A Case Study of the Messinian Gypsum in the Sorbas Basin (Almería, Spain). Minerals 2023, 13, 136. [https://doi.org/10.3390/min13020136] https://hdl.handle.net/10481/81101 10.3390/min13020136 eng http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Atribución 4.0 Internacional MDPI