Dating of the lower cretaceous Mauretanian flyschs of the Maghrebide chain: the Jbel Tisirene Formation (Rif, Morocco)

The Jbel Tisirene Formation (Rif, Morocco) is representative of the Cretace ous flyschs of the internal, or 'Mauretanian', part of the Maghrebides flys ch basin. We have dated, with Calpionellids and nannoflora assemblages, Ear ly Berriasian to Middle Albian terms in the Jbel Tisirene and Ras Cires sec tions. This disproves previous interpretations attributing this formation e ither to the Late Cretaceous or just to the Albian. Sand input was suddenly interrupted in the Middle Albian due to a eustatic phenomenon related to t he incipient connection between the central and southern Atlantic. ((C) Aca demie des sciences / Elsevier, Paris.).