Texture and composition of the Rosa Marina beach sands (Adriatic coast, southern Italy): a sedimentological/ecological approach

摘要

Beach sands from the Rosa Marina locality (Adriatic coast, southern Italy) were analysed mainly microscopically inorder to trace the source areas of their lithoclastic and bioclastic components. The main cropping out sedimentary unitswere also studied with the objective to identify the potential source areas of lithoclasts. This allowed to establish howthe various rock units contribute to the formation of beach sands. The analysis of the bioclastic components allows toestimate the actual role of organisms regarding the supply of this material to the beach. Identification of taxa that arepresent in the beach sands as shell fragments or other remains was carried out at the genus or family level. Ecologi-cal investigation of the same beach and the recognition of sub-environments (mainly distinguished on the basis of thenature of the substrate and of the water depth) was the key topic that allowed to establish the actual source areas ofbioclasts in the Rosa Marina beach sands. The sedimentological analysis (including a physical study of the beach andthe calculation of some statistical parameters concerning the grain-size curves) shows that the Rosa Marina beach isnowadays subject to erosion.