Location and extent of the Biscay, Basque-Cantabrian and Pyrenean rifts in the context of the North Iberian hyperextended rift system. The map also displays major described Alpine thrusts. Basque-Cantabrian and Pyrenean rift segments and related structures are from Lescoutre and Manatschal (2020). Biscay and Llanes rift segments and their bounding breakaway structures and the Le Danois Thrust (LDT) are from Cadenas et al. (2020). The inset map displays the location of the studied zone in the context of the Pyrenean-Cantabrian orogen. BWF: Biscay Wedge Front (from Fernández-Viejo et al., 2012); CMF: Cantabrian Mountains Front (from Alonso et al., 1996); LDD: Le Danois Breakaway surface; LLD: Llanes Breakaway surface; NPFT: North Pyrenean Frontal Thrust; NMD: North Mauléon Detachment; SPFT: South Pyrenean Frontal Thrust; SMD: South Mauléon Detachment; STZ: Santander Transfer Zone (from Roca et al., 2011).