Seismotectonics of the Southern Apennines and Adriatic foreland: insights on active regional E-W shear zones from analogue modeling

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
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.

INGV, Università degli Studi di Pavia