Archaeological evidence for Roman-age faulting in central-northern Sicily: Possible effects of coseismic deformation

We analyzed displacement on man-made structures and destructive effects on the ancient Roman community in two archaeological sites located on the southernMadonie Mountains, central-northern Sicily. At the archaeological site of MountAlburchia, a votive niche of the Late Roman period is offset ~15 cm by a NNW-SSE–striking normal fault belonging to a NNW-SSE–trending en-echelon system related toan E-W–oriented regional shear zone. Structural analysis of deformed conglomeratessuggests a coseismic origin of displacement. At the Gangi Vecchio archaeological site,3 km northeast of Mount Alburchia, the prevalence of pottery pieces and coins datedfrom the fourth century B.C. to the fourth century A.D. and a sudden decrease of evidence of human activity at the end of the fourth century A.D. have been emphasizedby archaeologists. Furthermore, recent archaeological excavations have revealed a Roman-age grave where remains of some women and children are mixed. Because ancient Romans usually did not use common burial, this could be related to an unexpected natural disaster. This event was conceivably a strong earthquake that probablyoccurred in the Late Roman period. An analysis of historical catalogues suggeststhat this event could be referred to the A.D. 361 earthquake, the epicenter of which, in central Sicily, is poor defined. Our data represent a first step for the relocation of this seismic event northward in the Madonie Mountains area.