New geological constraints for the extension of the northern Apulia platform margin west of the Maiella Mt. (Central Apennines, Italy)

In this paper new outcrop data are provided for an under investigated area of the Maiella, located along the western limb of the thrust-related anticline. In this area, a seismic scale transect depicts a natural geological section across the northern Apulia platform margin. Stratigraphic and geometric characteristics allowed the recognition of a west-dipping segment, strictly related to the well known Maiella paleoescarpment. Features that concur to the escarpment definition are the abrupt contact between base-of-slope/basin and platform successions, the lateral shift of platform and slope time-lines across the paleoescarpment, and the presence of margin scallops and related megabreccias. This west-dipping escarpment segment coincides with a roughly north-south oriented break in the westward extension of the northern Apulia platform margin, and it indicates the presence of a basinal area developed to the west, in a north-south direction, between the Maiella and Morrone carbonate platform areas. Three different configurations of the northern Apulia platform margin are consistent with the interpretation of the outcrop data of the Maiella western flank. They can relate to a platform re-entrant of the northern Apulia margin, inherited from the Early Jurassic rifting of the continental margin, to a large-scale scallop formed during the mid-Cretaceous collapse of the platform margin, or to a tectonic backstepping of the platform margin, formed during the Late Cretaceous tectonic phase.