The textural and mineralogical features of Riva degli Angeli beach sands (Salento Peninsula, Southern Italy).

Riva degli Angeli beach (literally, Angel’s Shore) is an impressive portion of the coastal littorals characterizing the city of Porto Cesareo: one of the most wonderful landscapes and touristic attractions located in the Apulia Region Ionian side. It extends for 2.2 km between Punta Prosciutto and Punta Grossa headlands. From a naturalistic point of view, Riva degli Angeli covers a significant role, as it is part of the protected marine area (AMP) of Porto Cesareo. It is characterized by fifteen different habitats on the seabed, with a very high degree of representativeness of the Mediterranean submerged populations and a significant percentage of Posidonia Oceanica coverage. By a sedimentological point of view, it is a pocket beach (Milli et al., 2017) with no significant supply of sediment from adjacent sedimentary systems and therefore, the sands have an almost entire bioclastic origin. In 2016, a naturalistic engineering intervention was carried out in order to protect the dunes and to restore the coastline. While the intent to safeguard the entire beach environment from touristic activities and coastal erosion, a backshore nourishment procedure was conducted with uncertain provenance sands and unknown grain size. Indeed, the sands were compacted with Posidonia Oceanica layers forming a significant sand relief in the supratidal environments. After two years, the dune protections have been destroyed. The current beach profile contains few portions with a perfect flat top and a continuous erosional scarp (1.5m – 2.0m high) that causes the accumulation of Posidonia Oceanica at its base (Fig. 1). In this study, we show the results of some image analysis carried out on multitemporal orthophotos trying to recognize the beach evolution during the last 10 years. Two detailed sampling campaigns (2016 and 2018) were carried out in the backshore-foreshore-shoreface-offshore transition environments. Textural and mineralogical features of the sands have been analyzed in order to establish their variation within the beach and during the considered period