Sc, Y, Th, Cu and rare earth elements (REE) concentrations have been analyzed in 14 samples of surface
sediments by means of ICP-MS. Mean concentrations of Sc, Y and Th in these sediments are lower than
those presents in the Upper Continental Crust (UCC). Cu concentration is very high and is caused by
inputs from the Odiel and Tinto rivers, affected by acid mine drainage. åREE mean concentration is lower
than that observed in other rivers and estuaries. Plots of North American Shale Composite (NASC)-normalized
REE data of surface sediments show a slight depletion in REE concentrations. Most samples present with
middle REE enrichment relative to light REE and heavy REE