WNW-ESE profile in the Mauléon Basin showing the interpretation of the SWT model (A), the LET model (B), the seismic reflection profile (C) and the geological interpretation (D). Note the very high velocity body in the western Mauléon segment of the section, contrasting with the complex velocity inversion in the eastern Mauléon segment and the low velocity body in the Chaînons Béarnais segment, highlighting the importance of the Saison and Barlanès TS for the along-strike orogenic architecture of the study area. Correlating this section with the N-S sections further reveal that the intermediate unit bracketed by two velocity inversions in the eastern Mauléon segment should be the tip of the European Unit i.e., the European indenter between two thrusts.