Sand provenance of Le Dune and Torre Guaceto beach (Southern Italy).

The sandy littoral sectors of the Apulia Region (Southern Italy) show a large textural and compositional variability of the beach sands characterizing the different sedimentary dynamics of the Ionian and Adriatic coastal areas. The study areas include two Apulian pocket beaches (Torre Guaceto and Le Dune beach) which are representative of the coastal dynamics of a large sector of the central/northern Mediterranean Sea involving southern Adriatic Sea and northern Ionian Sea. Torre Guaceto beach is a 1 km littoral stretch located on the Adriatic Sea. Beach sediments range between coarse and fine sands and they include siliciclastic minerals and carbonate granules. Le Dune beach is located along the Ionian Seaside and develops for about 800 m. Beach sediments range from very coarse to mediumfine sands and they are mainly made up of bioclast fragments. Both study areas are part of marine protected reserves which includes 15 different habitats of the typical Mediterranean submerged populations and the presence of Posidonia oceanica meadows. Sedimentological, compositional and ecological investigations allowed describing the textural and petrographic characteristics of the beach sands by interpreting their sand provenance. The physical/biological interactions led us to analyse the beach sedimetary dynamics which is fundamental for pocket beach conservation. The sand compositional study highlighted the presence of mixed hybrid sands (terrigenous and bioclastic) and a longshore significant composition variability at Torre Guaceto beach, whereas the carbonate component (bioclasts more than 90% and lithics) represents the main element of Le Dune beach.