Sediment provenance of a carbonate bioclastic pocket beach — Le Dune (Ionian Sea, South Italy)

Abstract

This study focuses on the analysis of a carbonate bioclastic pocket beach located along a coastal sector of the Apulia Ionian Sea, Le Dune beach, South Italy. The beach develops for about 800 m and it is exposed to the south-westerly and southerly seas. Coastal sediments range from very coarse to medium–fine sands and they are mainly composed of bioclasts (more than 90%) which include molluscs, foraminifers, echinoderms, algae branched, bryozoans, spicules of sponges and arthropods. The study area is one part of a marine protected reserve characterised by 15 different habitats of the typical Mediterranean submerged populations and the presence of Posidonia oceanica meadows. The aim of our research is to highlight the correlation between physical and biological processes influencing Le Dune beach dynamics and its sediment provenance by analysing the textural and compositional characteristics of beach sands, which is fundamental for pocket beach conservation. The beach sand analysis, deriving from textural, compositional and bioclast investigations, underlines that one of the main indicators of the beach dynamics is the bioclast component, which provides relevant information about sand provenance and sediment transport. The beach constitutes a semi-close system only nourished by the shells of organisms and by the erosion of headlands and dunes without important sediment interchange with adjacent littoral sectors.