Morphotectonic evolution of the Adriatic piedmont of the Apennines: An advancement in the knowledge of the Marche-Abruzzo border area

This study focuses on the morphotectonic evolution of the Apennines Central Adriatic piedmont, and in particular on the region along the Marche-Abruzzo border. Stratigraphically, the rocks of this area are typical of a marine environment which characterised the Central Periadriatic Basin up to the Early Pleistocene. A differential regional uplift produced a north-eastward tilting of the area; this led to the development of a parallel drainage network across the emerged coastal plain during the Middle Pleistocene. These tectonic events, along with a series of climatic changes during the Quaternary, caused alternating phases of fluvial incision and deposition, which eventually produced four levels of fluvial terraces. As outcropping lithologies seldom display a full record of significant tectonic deformation, we carried out morphometric analysis, along with a geomorphological survey, in order to enhance our morphotectonic understanding of the area and to better define the role of neotectonics in the morphological evolution of the area. We also analysed the morphological evidence of tectonics, including field surveys focusing on fluvial and alluvial fan terraces, as they are valuable indicators of neotectonic evolution. Finally, we employed geostatistical analysis to facilitate the detection of fluvial terraces, even when affected by neotectonics. Our results indicate an active control on drainage evolution by NW-SE to WNW-ESE tectonic lineaments, intersected by SW-NE and WSW-ENE ones. These tectonic lines continued to be active up to the formation of the third level of terraces (Late Pleistocene). River captures and diversions followed during the Late Pleistocene and the Holocene, in some cases favoured by passive tectonic control. (C) 2008 Elsevier B.V. All rights reserved.