Collapses in Calcarenitic Deposits Along the Sides of the Ginosa Ravine in South Italy

Acollapseoflargestretchofacalcareoussandstonecliffoccurredinthe night between December 2nd and 3rd, 2017, on the upper levels of the right side of the deep narrow valley called Gravina di Ginosa, Apulia, southeast Italy. This event happened during a nonparticularly rainy period and, apparently, without a clear external triggering component. Even if the involved rock mass is not particularly extended, the collapse had a strong impact on the local community, since it involved part of the archaic rupestrian settlements of the ancient town of Ginosa. Several rupestrian grottoes were damaged, as well as the collapsed mass damaged some ancient inhabited buildings, at the lower levels of the valley. Here, this event is described and analyzed with remote sensing approaches and laboratory tests on rock samples. Moreover, the particular geomorphological and geological features of the area are emphasized, together with the effects on the stability related to the digging of artificial caves on the calcarenitic flank of the valley.