Gravel deposits in the El Tesoro basin host exotic-Cu mineralization and also contain interbedded paleosols, which record the Eocene-Miocene palaeoclimate history of the basin. Three paleosols (calcisol, gypsisol/vertisol and gypsisol) and a wetland deposit were selected to unveil the climate/environmental signal related to the infill of the basin. Intensity of magnetic susceptibility at two frequencies and Curie temperature, were measured to obtain the magnetic signals of sediments, thus magnetic susceptibility is higher for gravel and sand samples respect to mud samples as well as for more humid paleosols, also frecuency-dependent magnetic susceptibility is low for gravel and sand, slightly higher for mud samples and high in the wetland deposit. Magnetic minerals in the sediments are magnetite, titanomagnetite and titanohematite. The achieved results shows that there is a transition on paleosols from calcisol (less arid) to gypsisol (more arid), which is recorded by the concentration of Fe-oxides consistent with a regional climate trend, while in the mud from the wetland deposit there is only authigenic Fe-oxides, reflecting a local environmental trend. Magnetic properties on sediments from El Tesoro basin are useful to understand the climate/environmental context on which the basin was filled and the exotic-Cu mineralization was form.