Deep Seated Gravitational Slope Deformations and Large Landslides Interfering with Fluvial Dynamics; Examples from Central Apennines (Italy)

The study, developed over a wide mountain sector of the central Apennines (Italy), highlights the role of Deep Seated Gravitational Slope Deformations (DSGSD) in the evolution of a mountain portion of the Chienti river valley. Radiocarbon dating and geomorphological considerations, testify that a lateral spreading, developed on a large scale, has triggered large landslides in correspondence of the thalweg. These phenomena have repeatedly dammed the river bed (certainly since the end of the late Pleistocene) creating temporary lakes which lasted also for a long time. The high seismicity and the persistence of conditions favorable to the development of gravitational phenomena, in an area currently occupied by an important communication route, attest to the high degree of risk present in this sector of the Apennine