A deep-seated roto-translational landslide in flysch rocks in the Northern Apennines (the Casale-Colla landslide, Ferriere, Italy)

This study presents a detailed map and reference cross-sections of the Casale-Colla landslide in the Northern Apennines (Municipality of Ferriere, Province of Piacenza, Italy). It is an active deep-seated roto-translational slide in flysch rock masses causing significant damage to roads and hamlets. The map results from a comprehensive geological and geomorphological characterization supported by multitemporal aerial images, high resolution digital terrain models, displacement monitoring, boreholes and geophysics. The map and the cross-sections show that the landslide comprises five main sub-units, controlled by multiple sliding surfaces extending to a depth of 40 m. Monitoring data indicate that landslide velocity decreases from the upper to the lower sub-units, suggesting overthrusts between them, that the landslide comprises five main sub-units. The results demonstrate the added-value of integrating conventional investigations and remote-sensing datasets for the analysing and mapping of complex deep-seated slope instabilities.