Evoluzione quaternaria e dinamica attuale della fascia costiera di Fiume Santo (Sassari, Sardegna)

Abstract

The paper refers on the results of investigations carried out on the submerged portion of the coastal area of the River Santo (up to -20 m below sea level) and on land in the area facing the Enel (the National Electricity Board) Thermoelectric Power Station in the industrial area of Porto Torres (northern coast of Sardinia). This part of the coast, which has been slightly subsiding since late Tertiary times, is formed by huge amounts of fluviatile deposits (conglomerate and clayey soils). From early-middle Pleistocene times, deposition near the coast is a sheet flood type. The series of fluviatile deposits are distinguished into two formations: the so-called "Scala Erre" and "Fiume Santo" Formations, which were cut by the coastline in Tyrrhenian times. The upper Pleistocene hydrographic net incised both the formations. Evidence of this erosion are visible also on the submerged surface. Measurements of variations in sea bottom morphology indicate movements of mobilized sand in the order of 28.616 m3/y.