Development of Pleistocene Fluvial Terraces on the Eastern Frontal Sector of the Southern Apennines Chain, Italy

Abstract

The investigation of Pleistocene fluvial terraces in the small river valley of the Pescogrosso Stream and surrounding areas has shown a complex and positive location for the study of a fluvial catchment development. The Pescogrosso Stream is a left tributary of the Sinni River and is placed on the eastern front of the fold-and-thrust belt of the southern Apennine chain of Italy. Sedimentological and geomorphological analyses of eight fluvial terraced units revealed that their formation and evolution were strictly controlled by regional tectonic uplift of the Ionian arc, by climatic changes, and by sea-level variations. In particular, the Ionian sea-level oscillations, as a factor in controlling the short-term fluvial terrace development, was the main factor responsible for the three older terraces’ evolutions. Conversely, the evolution of the five younger terraces seems to have been controlled by the base-level variations of the Sinni River. Finally, the matching of much information derived from regional and local tectonics, the plot of longitudinal terrace profiles, and the application of a sequence-stratigraphic approach to fluvial depositional sequences allowed the recognition of three evolutionary stages of development in the Pescogrosso fluvial incised-valley system during Pleistocene times.