Molise and Apulia lie above a series of thrust sheets that were emplaced northeastwards on top of the foreland of the Adriatic Plate due to continental collision during the Neogene. In the southern part of the Apennines, the thrusting is no longer active, but it continues in northern Italy along the southern margin of the Po Plain. The foreland to the east is characterised by zones of active west-east trending dextral (right-lateral) strike-slip faulting. The best described of these zones is the Mattinata Fault, which has a clear topographic expression on the south side of the Gargano Peninsula and has been traced offshore into the Adriatic Sea. The estimated epicentre of the 1627 Gargano earthquake lies just beyond the western end of the known extent of the Mattinata Fault, although the link between the two remains uncertain.