In central-western Argentina, an Early Paleozoic belt including mafic-ultramafic bodies and marine metasedimentary rocks occurs along the western margin of the Precordillera and in the eastern Frontal Cordillera. In this paper, we present the analysis of aeromagnetic data and its processing focused on mapping geological limits, structures and the relation at depth of the southern Precordillera. With this main objective were applied filtering algorithms, reduction to the pole, tilt derivative, analytic signal, and particularly, the use of Improved Logistic Function (IL) as a new method of edge detection, in combination with the inversion map obtained from the Magnetization Vector Inversion (MVI) method. The results allow us to describe at depth the main trend of the Southern Precordillera Mafic Ultramafic Belt as two separated bocks, one in Peñasco and another in Cerro (Co.) Cortaderas, passing through Cerro (Co.) Pozos with a possible NNE-SSW direction. The combination of this techniques also can be used as prospecting guide to Pb–Zn–Ag vein deposits and High sulfidation Au-Epitermal deposits. •Determination of the Precordillera Mafic-Ultramafic Belt.•Linkage of maximum susceptibility, IL filter, outcrops of Mafic Ultramafic rocks and structural lineaments.•Magnetic Susceptibility 3D Model.