Discovery of Versilian deposits suitable for beach nourishment on the continental shelf of Western Liguria

Abstract

In this paper we present the results of a study conducted in collaboration with the Ligurian Region, in the framework of the E.U. Beachmed-e Interreg IIIc Project, to distinguish relic coastal deposits on the continental shelf, suitable for beach nourishment. These deposits are related to transgressive-regressive sedimentary cycles, and they are due to Quaternary glacio-eustatic sea level variations. In fact, during the sea level low stand associated with the last glacial maximum (c.18–20,000 yBP) the sea level was 110–120 m lower than its present level and the continental shelf was exposed. During the Versilian Transgression the coastline migrated from the shelf break to its present position. This migration was not continuous and conspicuous sediment bodies, associated with deltaic or littoral systems, were deposited during static periods. The results of a marine geology campaign with seismostratigraphic and sedimentological analyses enabled us to distinguish gravelly and sandy littoral deposits at depths of 20–40 m near the coast and 60–80 m on the outer shelf, in areas with only a thin Holocene mud cover (high stand deposits).

Keywords:

• high-resolution seismic stratigraphy
• regression-transgression
• sedimentary deposits

Acknowledgements

This work has been carried out within the framework of the BEACHMED (UE Interreg III B) and BEACHMED-e (UE Interreg III C) Projects.