Influence of particle size on geochemical suspended sediment tracing in Australia

Abstract

Suspended sediment tracing is a potentially useful method to identify the sources of suspended sediment in rivers. Sediment tracing relies on the use of representative and conservative tracers. Particle size is known to influence sediment geochemistry and yet its quantitative impact on sediment source discrimination is little known in Australia and worldwide. This paper investigates the influence of particle size on geochemical sediment tracing in southeastern Australia. The effects of particle size on sediment source discrimination are investigated using a multivariate mixing model. The results suggest geochemistry is a useful tracer for metasediment dominated catchments. Element concentrations are enriched in the finer fraction, but the differences of particle size distributions between sources and mixture are not sufficient to result in differences in source discrimination. The study demonstrates the less than 63 μm fraction to be a representative particle size for geochemical suspended sediment tracing in the lithologically-uniform catchments of Australia. Show more