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

摘要

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. 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 preexisting 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; and (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.