We combine different methodologies normally used separately in exploration geophysics to obtain the topographies of the Moho discontinuity and the boundary between the upper and lower crusts by separating their effects in the Bouguer anomaly map. The SFM method was used to define the average depth of the layers causing the anomalies. The resulting three-dimensional model which reproduces the observed gravity anomaly was estimated by inverting the corresponding domains of the power spectrum. A good correlation exists between the calculated depths and the upper and lower boundaries of the layered lower crust observed along the reflection seismic lines in the area. ¿ American Geophysical Union 1996