New data on post-Eocene tectonic evolutionof the External Ligurian Briançonnais (Western Ligurian Alps)

The Iberia-Eurasia plate boundary east of the Pyrenees

“…9a) (Collombet et al, 2002), and led to a generalised left-lateral transpressional regime (Ford et al, 2006). As a consequence, SW-ward overthrusting of the internal units onto the external ones took place (Kerckhove 1969;Merle 1982;Coward and Dietrich, 1989;Fry, 1989;Michard et al, 2004;Dumont et al, 2011Dumont et al, , 2012, together with the left-lateral juxtaposition of units initially belonging to different tectonic domains (Lemoine et al, 2000;Ford et al, 2006;Piana et al, 2009;d'Atri et al, 2016).…”

“…The present-day structural setting and the relationships between the different tectonic units of the Marguareis area are mainly controlled by the WNW-ESE Limone-Viozene transpressive shear zone (Piana et al, 2009;d'Atri et al, 2016). This zone developed during the above-mentioned Alpine left-lateral strike-slip stage and produced the SW-ward transpressive re-imbrication of the external Briançonnais rocks onto a stack made of the buried Dauphinois-Provençal foreland succession, tectonically capped by the Helminthoides Flysch units of the internal Piedmont-Ligurian Domain.…”

“…The Marguareis Unit in turn includes a western, central and eastern domain divided by N-S striking faults, as later detailed. The Limone-Viozene Zone (Piana et al, 2009;d'Atri et al, 2016) is defined as a regional WNW-ESE elongated tectonic unit extending for some tens of kilometres. In the study area, such a zone involves rocks of the external Briançonnais domain, and it is delimited by two main faults, namely the southern and northern Limone-Viozene boundary faults (Fig.…”

“…is locally affected by a pervasive foliation, particularly nearby the Limone-Viozene boundary faults, which documents a strong localization of the deformation in anchizonal metamorphic conditions . Instead, the Permian-Jurassic stratigraphic succession experienced much less internal deformation, allowing for the preservation of most of the primary stratigraphic features (Piana et al, 2009;Bertok et al, 2011Bertok et al, , 2012Martire et al, 2014).…”

Basin topography and depositional styles controlled by collisional tectonics in the Alps-Apennines junction (Tertiary Piedmont Basin, NW Italy)

“…Red lines show the Alpine related tectonic lineaments whereas in blue are the Apennine ones. CA: Canavese; IV: Ivrea-Verbano zone; SA: Southern Alps; IL: Insubric Line; SC: Stura Couloir Line (Giglia et al, 1996); CP: Cicatrice del Preit Line (Lefevre, 1983); LV: Limone-Viozene deformation zone (Piana et al, 2009;d'Atri et al, 2016); RFDZ: Rio Freddo Deformation Zone; OLL: Ottone-Levanto Line; SVZ: Sestri-Voltaggio deformation Zone; VVL, Villavernia-Varzi Line; CS, Celle-Sanda Line; TH: Torino Hill; MO: Monferrato area; MN: Monregalese area; SV: Savigliano; LA: Langhe; AM: Alto Monferrato; AL: Alessandria; BC: Borbera-Curone. Modified from Ghibaudo et al (2014).…”