NEW CALCAREOUS NANNOFOSSIL DATA ON THE CRETACEOUS-EOCENE AGE OF CORSICAN TURBIDITES

A detailed biostratigraphical study based on calcareous nannofossils has been carried out on the following Cretaceous-Eocene flysch of Alpine Corsica: Macinaggio Flysch, Tralonca Flysch, Vezzani Flysch, Balagne Calcareous Flysch, Lydienne (Toccone Unit), Palasca Sandstones, Gare de Novella Sandstones, Alturaia Arkoses. The bad preservation of calcareous nannofloras due to dissolution and overgrowth phenomena, did not permit the recognition of precise biozonal intervals; although many samples were barren, calcareous nannofossils provided further information about the Corsican flysch age and they often confirmed the previous age determination based on Foraminifera. The Macinaggio Flysch, ascribed in literature to the Cenomanian, has been referred to an age not older than latest Coniacian; the Balagne Calcareous Flysch, previously referred to the Eocene and, subsequently, to the Senonian, is Cenomanian and latest Coniacian-Campanian in age; for the Palasca Sandstones the Eocene age has been confirmed; the Lydienne (Toccone Unit) has been referred to an age not older than Late Albian; in the Gare de Novella Sandstones a Late Albian age has been recognized. These new data would suggest an older Cretaceous age for the beginning of the Corsican flysch deposition (Albian-Cenomanian) when compared to the Santonian and Maastrichtian ages of the Cretaceous flysch in the Northern Apennine. These results concerning the age of Corsican flysch together with the stratigraphic-structural and sedimentological data from the literature, provide new interesting considerations about the paleogeography of western Tethys.