Modes of fault reactivation from analogue modeling experiments: Implications for the seismotectonics of the Southern Adriatic foreland (Italy)

The active tectonics at the front of the Southern Apennines and in the Adriatic foreland is characterized by E–W striking, right-lateral seismogenic faults, interpreted as reactivated inherited discontinuities. The best studied among these is the Molise-Gondola shear zone (MGsz). The interaction of these shear zones with the Apennines chain is not yet clear. To address this open question, we developed a set of scaled analogue experiments, aimed at analyzing: (1) how dextral strike–slip motion along a pre-existing zone of weakness within the foreland propagates toward the surface and affects the orogenic wedge; (2) the propagation of deformation as a function of increasing displacement; (3) any insights on the active tectonics of Southern Italy. Our results stress the primary role played by these inherited structures when reactivated, and confirm that regional E–W dextral shear zones are a plausible way of explaining the seismotectonic setting of the external areas of the Southern Apennines.