Geophysical characterization of a sand deposit in a small-scale mining in the central east region of São Paulo State, Brazil

This research employs Electrical Resistivity Tomography (ERT), Ground-Penetrating Radar (GPR), and Transient Electromagnetic (TEM) to characterize a sand deposit located in a small-scale mining (SSM) in Leme, São Paulo State, Brazil. The region has a high demand for sand, particularly in the construction industry. The applied geophysical methods provide complementary information. ERT and GPR data enable the investigation of shallow subsurface layers (up to ∼30 m), whereas TEM is employed to investigate deeper structures, reaching depths of up to ∼350 m. The integrated geophysical results allowed the identification of a geoelectrical stratigraphy down to a few hundred meters, characterizing both unsaturated and saturated sand layers. A 3D model of the sand deposit was built based on the geophysical results and lithological information from boreholes in the study region. This model includes the deposit's geometry, mass, and volume, which are crucial information for an economic assessment of the SSM. Moreover, our results demonstrate how near-surface geophysical methods can be employed to help with a sustainable exploration of a sand deposit in an SSM.