Magnetic properties of surface sediments from the Pearl River Estuary and its adjacent waters: Implication for provenance

Environmental magnetism has been widely used as a rapid, cost-effective, and non-destructive method in various fields including sediment source identification. Nineteen surface sediments from ten transects in the Pearl River Estuary (PRE) and its adjacent seas were studied for magnetic measurements. Combined with mineral analysis for representative sample's, magnetic implications for provenance are discussed. The results indicate that concentration-dependent magnetic parameters decrease gradually and change sharply between the PRE and its adjacent waters. The magnetic mineral assemblage is basically consistent at all sites, i.e. consisting of magnetite and hematite. However, the grain size of magnetite particles is clearly different probably due to different material sources. Magnetic parameters allow separating the sediments from the PRE and its adjacent seas into three groups, more distinctively than deduced from clay mineral analysis. These new findings indicate that magnetic properties of surface sediments bring complementary information of material source as well as marine geology.