Using critical-distance Moho reflections o fan-profiles, sections of the topography of the crust-mantle boundary across the Pyrenean mountain range are obtained. At two different places throws of more than 10km in the Moho are detected, they are situated beneath the same surface fault. Together with other features such as local dips, these results have a strong bearing on models of regional evolution. The existence of fractures through the continental lithosphere is documented by that simple technique using the Moho as a marker.