Simplified geologic map of the Argentera-Mercantour Massif (after Malaroda et al., 1970; Carosi et al., 2016; Gosso et al., 2019; and refs. therein). Black profiles highlight Valscura (a) and Val du Haut Boréon (b). Abbreviations: FSZ: Fremamorta Shear Zone; VSZ: Valletta Shear Zone (also known as Ferrere-Mollières Shear Zone). Projected coordinate system: WGS 84-UTM32N. Insert: tectonic sketch of the Alps: A: Variscan basement rocks into the axial zone of the Alps; B: Variscan basement rocks at the external margins of the Alps (Ag: Aar-Gothard Massif; Ar: Argentera-Mercantour Massif; Bd: Belledonne Massif; Mb: Mont Blanc Massif; Px: Pelvoux Massif; Sa: Southern Alps); C: Variscan basement rocks external to the Alpine fronts (Mt: Maures-Tanneron Massif, Vs: Vosges); D: lithospheric-scale structures delimiting the axial zone of the Alps (Pf: Penninic Front, Pl: Periadriatic Lineament); E: Alpine fronts.