North-Pyrenean foreland basin evolution during Palaeogene times (Adour basin): stratigraphic constraints.

The study of 50 wells correlated according to the principles of High Resolu tion Sequence Stratigraphy, shows that the Adour basin is filled during two main steps. (1) The Palaeocene is characterised by aggradational carbonate platforms, passing southward to turbiditic sedimentation. During this init iation stage, the carbonate production balances accommodation space creatio n. (2) The Ypresian-Priabonian is characterised by large progradational del taic systems, migrating westward. During this stage, siliciclastic supply w as higher than accommodation space creation. This basin is interpreted duri ng Palaeocene to Middle Eocene as a compressional basin due to lithospheric buckling. The foreland history starts during the Upper Eocene to Oligocene . (C) 2001 Academie des sciences / Editions scientifiques et medicales Else vier SAS.