Modelled gravity anomalies, predicted by model A (dashed black line) and model B (solid black line), centred at their minimum and compared to the observed residual gravity anomalies along sections SEC1, panels (a) and (c), and SEC2, panels (b) and (d), and for a crust density of 2670 kg m⁻³, panels (a) and (b), and 3000 kg m⁻³, panels (c) and (d). Different grey colours correspond to different values of mantle density and reference Moho depth used to retrieve residual gravity anomalies from observed Bouguer anomalies. Dark grey: mantle density 3400 kg m⁻³; reference Moho depth 20 km. Intermediate grey: mantle density 3400 kg m⁻³; reference Moho depth 30 km. Light grey: mantle density 3270 kg m⁻³; reference Moho depth 30 km. Shaded areas delimit data with latitude higher then 41°.