Erosive and depositional processes on shelf prodeltaic deposits linked to a "Fiumara" river in the Gulf of Patti (NE Sicilian margin)

The NE Sicilian continental margin formed as a rifted margin in relation to the opening of the Tyrrhenian back-arc basin. This area is affected by regional uplift at rates in the order of ca. 1 mm/a since Pleistocene, with higher local uplift associated with co-seismic vertical movements. Because of the rapid uplift, several short "fiumara" rivers with steep course deeply incise the coastal highlands. This kind of rivers typically go through seasonal periods of dry stream bed that alternate with short intervals of water supply during intense flash floods. During these events, the large amount of sediment and debris released at the river mouth possibly evolves into marine hyperpycnal flows. If the continental shelf is absent or dismantled by canyon heads, hyperpycnal flows are directly funneled into the upper slope. On the contrary, if a larger continental shelf is present, these flow can form linguoid or lobate deltaic system. In this study, we present the first results of an integrated analysis of high resolution multibeam bathymetry, backscatter, seismic data and seafoor sampling recently collected on the prodeltaic system developed off the mouth of Mazzarrà Fiumara (Gulf of Patti). Particular attention will be dedicated to constraint the genesis of seafloor waveforms and gullies that morphologically characterizes this prodeltaic system by using their morphometric parameters and comparison with similar study elsewhere. We also attempt to reconstruct the relationship between the observed erosional and depositional features on the background of the manifold processes that may have contributed to the stratigraphic growth and geomorphic shaping of this deltaic system.