Geological map of the middle Orco Valley, Western Italian Alps.

Detailed mapping of the middle Orco Valley in the Western Italian Alps allowed for the reconstruction of the lithostratigraphy and the structural evolution of different tectonic units along a geological section from the Gran Paradiso Massif to the Gneiss Minuti Complex of the Sesia-Lanzo Zone. The studied nappes can be grouped into a Lower Tectonic Element which underwent eclogite facies metamorphism and an Upper Tectonic Element pervasively equilibrated under greenschist facies conditions and lacking evidences of high pressure metamorphism. The mapping of Quaternary deposits, geomorphological features and brittle structural elements provided evidence for the occurrence of a deep-seated gravitational slope deformation on the left side of the middle Orco Valley.