North-South lithostratigraphic columns of the five studied synclines and their basement. Thicknesses are extracted from references mentioned below each column. Stratigraphic groups are initially defined by Ford et al., (2016) and then adapted by Rougier et al., (2016); Grool et al., (2018); Angrand et al., (2018); Ford and Vergès (2020); Crémadès et al., (2021) and this study for the Corbières region (see text for details). BRGM codes are reported for each formation. Series crossed by the Yvroux borehole of Rennes-les-Bains are indicated by a solid red line (and a dotted line when series are absent beneath the well location). Horizontal sinuous lines represent stratigraphic gaps (erosional surfaces).