Tracing the Source of the Bio/Siliciclastic Beach Sands at Rosa Marina (Apulian Coast, SE Italy)

Abstract As the transitional zone between land and sea changes in time from erosional to sedimentary, and as sediments can be supplied by a wide variety of marine, fluvial, and aeolian processes, it is commonly difficult to trace the source(s) of beach sediments. The sands consist almost exclusively of bioclastic components and quartz. Reconstruction of the potential source areas, on the basis of composition, analysis of the texture, and grain-size analysis of the sands, shows that the beach sands, which are now subject to erosion, are derived most probably almost exclusively from eroded nearby rocks, and that particularly organisms living in the uppermost 6 m of the sea contribute most of the material. Analysis of the bioclasts shows that a wide variety of marine organisms contribute. The siliciclastic components are derived (nearly?) exclusively from wave-eroded lithified sandy sediments. This implies that supply from the two nearby streams and by longshore transport is negligible.