The role of pre-existing faults in the structural evolution of thrust systems: Insights from the Ligurian Alps (Italy)

摘要: Abstract New structural and stratigraphic data for a selected area of the Ligurian Alps are combined in order to assess discuss role played by extensional structures southernmost segment Western during thrusting. Restored cross-sections field suggest that style external sector chain may depend upon presence pre-orogenic normal faults ascribed three events linked different geodynamic contexts: (i) Permian post-Variscan plate reorganisation, (ii) Mesozoic rifting–drifting phases leading opening Alpine Tethys, (iii) Eocenic development European foreland basins. During positive inversion Eocene times, thin-skinned thrust system developed this area, followed thick-skinned phase. In both situations inherited fundamental roles: phase they conditioned thrusting sequence, also producing large-scale buckle folds partial reactivations; strain was compartmentalized partitioned pre-existing faults. The kinematic model sectors allows re-assessment evolution front-foreland transition, including: indirect confirmation Brianconnais Dauphinois domains were not separated Valais-Pyrenean oceanic basin; progressively changed into thick-skinned; assertion there no significant deformations from Oligocene present-day, Corsica–Sardinia block rotation only produced change orientation previously formed fault development.