Fabric/shear zone mapping protocol from aeromagnetic data and its validation illustrated for the Koudougou quadrangle (location on Fig. 1): (a) aeromagnetic map; (b) interpretative fabric trajectories with field measurements of Chèvremont et al. (2003); (c) interpretative shear zone pattern. The longest NNE-trending shear zone is the Ouahigouya shear zone (Fig. 3); (d) Faults/shear zones from earlier mapping works (Chèvremont et al., 2003; Baratoux et al., 2011); (e) interpretative pattern of the main mafic dikes. Geological contours are modified from Castaing et al. (2003).