The geology of the San Leo Cliff (Northern Apennines, Italy)

The main objective of this work is to deduce the geologic setting of the San Leo cliff from the natural sections exposed in its own rock walls. The line-drawings of the rock walls, coupled with a detailed geologic map and framed in a tectonostratigraphic scheme, allow us to reconstruct a 3D geological model of the San Leo cliff. The interpretation of the collected data also allows us to establish the relationships between lithostratigraphy, tectonics and geomorphology that control the evolution of this spectacular and delicate landscape emergency of Val Marecchia. The 2014 landslide (Benedetti et alii, 2015) has been only the latest event in the evolution of the San Leo cliff, where fractures and faults of Late Pliocene to Present age have predisposed rock masses to fall, so that the current slope morphology is the result of a very long series of rockfalls (Benedetti et alii, 2011).