The Alps-Apennines Interference Zone: A Perspective from the Maritime and Western Ligurian Alps

In SW Piemonte the Western Alps arc ends off in a narrow, E-W trending zone, where some geological domains of converged. Based on critical review available data, integrated with new field it is concluded that southern termination recorded Oligocene-Miocene activity regional transfer zone (southwestern Transfer, SWAT) already postulated literature, which should have allowed, since early Oligocene, westward indentation Adria, while shortening and tectonic transport toward SSW (Dauphinois foreland) was continuing. This corresponds to system deformation units km-scale shear zones (Gardetta-Viozene Zone, GVZ). The GVZ/SWAT developed externally Penninic Front (PF), here corresponding Internal Briançonnais (IBF), separates domain, affected by major tectono-metamorphic transformations, from External Briançonnais, subjected only anchizonal metamorphic conditions. postcollisional evolution axial belt Oligocene Miocene inner syn-orogenic basin (Tertiary Basin, TPB), rests also Ligurian stacked within adjoining Apennines Piemonte. TPB successions were controlled transpressive faults propagating (to E NE) previously formed Alpine belt, as well Apennine thrusts progressively stacking units, resting subducting Adriatic continental margin, themselves. allows correlation between kinematics, terms age main geologic events, interference structural systems control exerted both belts same basin.