Cenozoic shelly sands in the Cotentin (Armorican Massif, Normandy, France): A record of Atlantic transgressions and intraplate Cenozoic deformations

Three episodes of Cenozoic tidal shelly sands (‘faluns’), dated to the Middle Eocene, Middle Miocene, and Plio-Pleistocene, were deposited by transgressions over the Northeast of the Armorican Massif (Cotentin, Normandy, France) during highstand eustatic sea levels. These shelly calcareous sands and gravels were deposited behind Palaeozoic rocky shoals that separate the Cotentin Basin from the Atlantic Ocean. The morphology of the Cotentin Basin persisted through the Palaeogene and Neogene times with smooth slopes, despite the Cenozoic eustatic sea-level fluctuations and uplifts that affected the Armorican Massif and its borders.