Late Quaternary geomorphological evolution of the Adriatic coast reach encompassing the Metauro, Cesano and Misa river mouths (Northern Marche, Italy).

This work has been carried out to gain deeper insights on the late Quaternary geomorphic evolution of the Adriatic costal area encompassing the Metauro, Cesano and Misa river mouths, in the outer sector of the northern Marche Apennines. In addition to detailed geomorphological survey, drilling logs and data from new and previously reported radiocarbon datings, a geostatistical processing of fluvial and marine terrace topography was attempted, which is finalized to reconstruct the original geometry of depositional top-surfaces. The Metauro, Cesano and Misa rivers in their most distal sectors flow orthogonally to the coastline and display wide and flared fluvial plains in the proximity of their mouths. At least four fluvial terrace levels, likely referred to Middle Pleistocene-Holocene glacial-interglacial cycles have been recognized throughout the study area. Fluvial plains generally merged into narrow relict coastal plains interconnecting the river mouths, and coastal fans affected by wave-cut scarps are the main geomorphic features of the coastal area. Close to the river mouths the bulk of geomorphic and geometric/stratigraphic features were consistent for identifying, for the first time, some typical coastal fans with well preserved Holocene wave cut scarps. Further, data indicate that the local convex-up morphology and the geometric assessment of the topography depend upon the fan location rather than tectonics. Finally, by coupling geomorphologic and stratigraphic data with the results of geostatistical analysis, it has been possible to constrain the location of shoreline and sea level during the last Interglacial. Basing on that, it has been calculated that the coastal area underwent a mean uplift rate of at least 0.15 mm yr-1, in fair agreement with previous estimations concerning the northern Marche coastal zone.