Basque-Cantabrian Basin

The Basque-Cantabrian Basin is an area of 250 x 100 km located in the extreme west end of the Pyrenees Mountains. It is a Mesozoic and Tertiary sequence on a Hercynian (Devonian-Carboniferous) basement and the stratigraphic colum shows continuous series of sediments from the Permo-Triassic through the Tertiary, reaching a thickness of 15,000 metres, including evaporites, carbonates, clastics and volcanics. The basin was formed during the stages of rifting and opening of the North Atlantic (Bay of Biscay: separation of the Iberian and European plates) due to deformation due to the collision of the Iberian and European plates from the Maastrichtian through the Oligocene. The Pyrenean phase of the Alpine Orogeny (Eocene-Oligocene) deformed the sedimentary series, uplifted the sedimentary section and inverted the basin.