Since the Cenomanian, the Aquitaine Basin is under the influence of the Pyrenean orogeny with its west-northwest-east-southeast-striking structural grain. The Pyrenean orogen likewise has not merely a compressional origin but also a strong, in this case, sinistral transtensional component. The Pyrenean orogen exerted a very profound influence upon the Aquitaine Basin up to this day, subjecting it not only to more or less north-south-directed compression but also to transtension. The effects were of a penetrative nature—tectonic repercussions of the Pyrenean orogeny can even be seen at the northeastern basin margin in the immediate vicinity of the Massif Central.