DEEP-SEATED GRAVITATIONAL SLOPE DEFORMATION EFFECTS ON QUATERNARY DEPOSITS IN THE WESTERN ALPS (NW ITALY)

Abstract

Deep-seated gravitational slope deformations (DSGSDs) are well-known to affect the landscape and the morphology of Alpine valleys. In contrast, little is known on their influence on Quaternary deposits. This paper, focused on the Western Italian Alps, aims to fill this gap. Eight case studies, identified after a long term field experience, are presented, representative of different geological settings. To fully define their distinctive features, such sites have been characterized using various methods: geological surveys, geophysics and geomatic techniques. DSGSD proved to influence the sediment deposition primarily with the continuous supply of centimetric/decimetric angular clasts. This have different consequences on sediments, depending on their features, in some cases deeply modifying their typical facies (i.e., glacial, colluvial and lacustrine sediments), whilst in other cases their influence is less evident (i.e., debris, avalanche and torrential deposits). This paper can be a useful tool when dealing with DSGSD-related deposits, helping avoid misinterpretations.