Baseline of distribution and origin of Rare Earth Elements in marine sediment of the coastal area of the Eastern Gulf of Tigullio (Ligurian Sea, North-West Italy)

Abstract

A study on the Rare Earth Element (REE) distribution in the bottom sediments of the Gulf of Tigullio (north-west Italy) was conducted. The results constitute a baseline for this zone of the Ligurian Sea and enabled the obtaining of valuable information on the origin and transport of sediments in the gulf. The distribution of REEs is controlled by phosphates, mainly monazite, and is generally homogeneous in the study area, reflecting the homogeneous distribution of the minerals. Some differences in REE and Sc distribution allow us to identify two sub-basins (Entella and Gromolo torrent sub-basins) characterised by slightly different geological frameworks. The "hat-shaped" observed patterns seem to indicate an overprinting of the original REE patterns due to exchanges between phosphates and seawater. REEs seem to be related with the rocks outcropping in the area, although an indirect effect of anthropic activity could be seen near a fish farm.

Keywords: Element distribution; Marine bottom sediments; Rare Earth Elements; Sediment input.