Chapter 9 Cretaceous Rifting at the Pyrenean Iberia-Eurasia Border: Crustal Thinning under a Pre-rift Cover - Application to Passive Margins
Résumé
The North Pyrenean Zone (NPZ) belongs to the northern flank of the Pyrenean chain and continuously outcrops to the north of the AZ from Perpignan to the Basque Country. It is essentially composed of Mesozoic sediments associated with Paleozoic basement massifs (North Pyrenean massifs) and results from the inversion and northward thrusting of the basins formed during the Cretaceous rifting phase. The geology of the NPZ is unique in the world and of major interest for the study of the formation of passive continental margins and, in particular, for better constraining the thermal conditions of crustal thinning. The NPZ is the result of the inversion of extensional and transcurrent structures distributed along the Iberian–Eurasian plate boundary. Along the Iberia–Eurasia boundary itself, the Basque–Cantabrian basin was connected to the North Pyrenean basins (future NPZ). The evolution of the Pyrenean smooth-slope basins contrasts with brittle-dominated models of crustal thinnings, as exemplified along the Iberian–Newfoundland passive margins.