The meaning and the space-and-time variable depositional features of the Ussana “Fm” and of the related
coeval units, base of the Late Oligocene - Miocene succession of the Sardinian rift, are discussed. These features, and
the presence/absence itself of the Ussana Fm, are related to tectonic and paleomorphologic characters of the Sardinian
rift shoulders and their evolution. The features of the Ussana Fm evidence the changing characteristics of the Sardinian
rift up to the southern Corsica area. Giving the extremely variable characters of the stratigraphic sections of the Ussana
Fm from S to N and also at short distance, a possible lithostratigrahic upgrade of the unit to litostratigrpahic group is
proposed