A mountain slope deformation in an alpine metaophiolitic massif (Ligurian Alps, Italy)

Deep-seated gravitational slope deformation (DsGSD) represents a relevant geological-geomorphological feature of the landscape and has drawn scientific attention for the past several decades. During a detailed fieldwork in the Ligurian Alps, we identified areas (larger than ca 5 km2), characterized by very low percentage of outcrops, with rock blocks on the watershed and many morpho-tectonic evidences. Through the integration of geological-geomorphological mapping, structural data, photo interpretation, GIS-based analyses, we identified a number of typical DsGSDs. The example here described is one major complex-sagging-type DsGSD that is not present in national land planning and/or management databases but that is likely at the origin of the large-scale landslides which affected the villages of the area. This DsGSD is also located within the Beigua UNESCO Global Geopark, in an area of unique natural and historical value. This study once again highlights the importance of ground truth observations as the basis for further investigations.