Cenozoic folding and faulting in the south Aquitaine Basin (France): insights from combined structural and paleostress analyses

New fieldwork, surface data (e.g. drainage network anomalies) and SPOT sate llite imagery are combined with sub-surface data (seismic profiles and dril l-cores) to analyse the structural setting of the south Aquitaine Basin. Ce nozoic paleostresses are determined through inversion of fault slip and cal cite twin data (quarries and drill cores), allowing reconstruction of the C enozoic structural and tectonic evolution. The main tectonic event, the NNE 'Pyrenean compression', from the Late Cretaceous to the Oligocene, is resp onsible for thrusting and folding along N110 degrees axes and strike-slip r eactivation of major NNW and NE-SW faults. Some fold axes turn along NNW ma jor wrench faults, and compression locally undergoes deviation to ENE trend s. NNE extension locally occurred at anticline hinges. After a minor WNW ex tension, a Miocene NNW compression occurred and changed into a perpendicula r ENE extension, responsible for nearly N-S normal faulting. These multiple states of stress reflect two major compressional events (NNE and NNW); their variety mainly reveals local accommodation due to numerous inherited structures, in the general context of Eurasia-Africa convergence . (C) 2000 Elsevier Science Ltd. All rights reserved.