Morphometric analysis of fluvial network and age constraints of terraced surfaces of the Ofanto basin, Southern Italy

The Ofanto basin is an intermontane depression located in an intermediate position between the axial zone and the thrust front of the southern Apennines, Italy, filled by Pliocene to Quaternary sediments of both marine and continental origin. This basin presents some peculiarities such as the orientation of the elongation axis with regard to the strike of the chain, marked anomalies of the drainage network, and the asymmetric distribution of the terraced surfaces. Our paper focuses on the morphotectonic evolution of such a complex intermontane basin and tries to explain all those characteristics. The results obtained from both quantitative and morphostructural analyses allowed us to reconstruct the Quaternary evolution of the basin, particularly referred to the ancient land surfaces and the younger fluvial terraces. The hypothesis of a long-term process driven by the differential tectonic behaviour of the two basin flanks instead of a pure litho-structural control responsible for the fluvial network asymmetry of the Ofanto River catchment is here presented and discussed.