Tectogenèse pyrénéenne dans le bassin flexural d'Aquitaine: apports de la reconstitution de paléocontraintes

Abstract

Paleostress reconstructions based on analyses of fault slips and mechanical calcite twins highlight the Cenozoic structural evolution of the Aquitaine basin. The pyrenean phase, from the Late Cretaceous to the Oligocene, corresponds to a N020 compression, responsible for the development of N110 trending folds, locally deviated near N160 ramps. Later, the compression turned to N160. Nearly east-west extensions, probably resulting from stress permutations, produced north-south normal faults. This tectonic evolution, dominated by a north-south compression, is apparently polyphase because of structural inheritance and salt tectonics.