Grain-size distribution and sand composition of barrier spit between Capo Suvero and Gizzeria village (Calabria, southern Italy)

The study analyses the sand composition and grain-size distribution of the backshore beach sediments forming a barrier spit between Capo Suvero promontory and Gizzeria village (Calabria, South Italy) on the Calabria Tyrrhenian coast. Previous studies mainly discussed the mineralogy composition of the offshore and backshore beach sands and the historical shoreline evolution of this coast stretch. The present study extends the previous works because it is based on a detailed composition and granulometric analysis of the beach sediments that built a spit in 2005 and dismantled a few years later. Twenty-seven beach samples were collected in 2005 within the backshore zone along three transects and analysed in this work. The achieved goals indicate that the granulometric analysis of the backshore sediment samples exhibits different peaks among the grain-size fraction ranging from pebble to coarse sediments, and the majority contain more than 60% (in weight) of the very coarse sand fraction, showing a high-energy environment. The sediment mineralogy consists of an assemblage dominated by Schist+Phyllite+Serpentinite lithic fragments. Therefore, metamorphic rock fragments are the dominant grain type in the backshore environment. Serpentinite lithic fragments testify its provenance from a small high-pressure and low temperature complex of blue schists outcropping in the Calabria Coastal Range. The detrital modes indicate a predominant source represented by the Savuto River flowing across the intermediate-lower crustal rocks forming the Coastal Range on the study area's north side. Therefore, the achieved goals testify that Capo Suvero promontory does not obstruct longshore sand transport as was recognised in previous work.