Over this time span, the basin acted as a foreland basin of the surrounding Cantabrian Zone and the Basque–Cantabrian Range in the north, the Iberian Range in the east and the Central System in the south, which constitute complex fold and thrust belts.
Over this time span, the basin acted as a foreland basinof the surrounding Cantabrian Zone and the Basque–Cantabrian Rangein the north, the Iberian Range in the east and the Central System inthe south, which constitute complex fold and thrust belts.