Marly Arenaceous

The Marly – Arenacea, consisting of arenaceous layers alternating with marls and pelites (fine-grained rocks), is a turbidite formation (turbidites are sedimentary bodies deposited by turbida currents, i.e. submarine currents). This formation occupies a very large area (Umbrian – Romagnolo Basin), which also extends over a part of the Marches where the Marnoso – Arenacea is found outcropped above the Schlier. The deposition of this formation was regulated and conditioned by the migration of the foredeep from the west to the east and led, starting from the lower – middle Miocene, to the identification of various Structural Domains (Umbrian – Marchigiana ridge, Marchigiana ridge, External Marchigiano basin and Internal Marche Basin). The migration of the foredeep has influenced the age of deposition of this stratigraphic unit with the identification of at least 4 members who are gradually younger as we move from west to east. The formation tends to give rise to particular morphologies in which the more resistant layers, the arenaceous bodies, tend to stand out in the landscape compared to the less resistant ones (peliti and marl).