This formation consisting of an alternation of marl and clayey marl and whitish marly limestone stratigraphically follows the Bisciaro formation to form horizons (levels) that often tend to make it difficult to distinguish the two formations. The name derives from similar contemporary deposits found in Austria within the Vienna basin. It is a hemipelagic formation (hemipelagic = environment where only the finest materials from the continent are deposited). The Schlier presents lateral variations with other Miocene formations (for example the Marls with Cerrogna in the southern sector of the Region). The age of formation tends to become progressively younger as we move from west to east, in accordance with the structuring phases of the Apennine chain and the migration of the chain – foredeep system during the Miocene.