The first two observed phases D1 and D2 form isoclinal* folds and are related to overthrusting movement* towards the N-NW as part of the emplacement of the Simano nappe*. D2 is responsible for the main schistosity* and N-S main lineation* in all lithologies*.

D3 causes the opening of tension gashes* and the crystallization of the tension gashes (also known as "Knauern*"), and is related to top-North shearing. This phase is contemporary of the Tertiary* Barrovian* peak of metamorphism* (peak of temperature, see next page) in amphibolites facies*, which is marked by the assemblage* kyanite, garnet and staurolite in metapelites* and hornblende (tschermakite), plagioclase and garnet or biotite in amphibolites*.

The D4 phase of West vergent* transverse folding* give rise to the dominant fold structures in the studied area, including the great Lareccio anticline*. This fourth phase is at the origin of a new coarse schistosity S4, which develops in the hinges* of the great fold structures.

This D4 phase occurs always in amphibolite facies and shows a deflection of the major lower Pennine* unities towards W during the tectonic exhumation* event.

The last D5 phase causes a coarse vertical crenulation* due to vertical shortening during last stage of the ductile deformation history.