A. Geological map of the Labourd Massif (modified after Genna, 2007), showing the main structural features and tectono-sedimentary units. Tectono-sedimentary breccias after Masini et al. (2014). B. Cataclasites affecting the Ursuya granulites, near the village of Bonloc. C. South-dipping foliation and boudinage related to the Louhossoa shear zone cross-cut by north-dipping extensional faults. D. Geological cross-section across the Labourd Massif showing the major structures and tectono-stratigraphic units (after Lescoutre et al., 2021).