Simplified geological map of the Pyrenees showing the location of the studied north pyrenean basins. 1: Foreland Basins (Aquitaine and Ebro); 2: South Pyrenean Central Unit (SPCU); 3: South Pyrenean Zone; 4: Sub-Pyrenean Zone; 5: North Pyrenean Zone; 6: Internal Metamorphic Zone (ZIM); 7: Border tectonic slivers Zones; 8: High Primary Belt; 9: North Pyrenean Massifs; 10: Sub-Pyrenean Massifs; 11: Montagne Noire; 12: South Pyrenean thrust sheets (Gavarnie in brown and SPCU in orange); 13: Main thrusts; 14: Main faults; 15: Hiden faults.