Provenance of Coastal Sediments Using Natural Radioactivity of Heavy Mineral Sands

Abstract

The radioactivity of heavy mineral sands, due to the inclusion in their crystals of U and Th, has proved to be a fast and reliable method for mapping surface occurrences of these minerals in dune and beach sands along the Dutch coast. A correlation was found between U and Th abundance and elements like Zr, P and, e.g. La, indicating a correlation between U, K and Th and the mineralogical composition. This correlation is used as an empirical 'radiometric finger print' of the sands. Concentrations of heavy mineral sands were not only found at the foot of dunes but also in the dunes and at places where former islands merged, indicating that during deposition heavy mineral concentration also occurs. Data for the island of Texel indicate the erosion of fluviatile sands in deeper tidal inlets and deposition of these sands on beaches.