Urban river sediments preserve a unique record of natural Earth-system processes and anthropogenic influences. This research investigates the distribution, fractionation, and anomalies of rare earth elements (REEs) in sediments from the Jukskei River in South Africa. The aim was to elucidate the influence of climate and anthropogenic activities on sediment geochemistry. ICP-MS was employed to analyse sediment samples from both the wet and dry seasons. The results were compared with Post-Archean Australian Shale to assess their enrichment levels. The functioning of redox oxidation-reduction conditions in ecosystems has been elucidated for both historical and contemporary contexts. The results show that the levels of light and heavy rare earth elements fluctuate depending on the changing seasons. This shows that climate influences redox and adsorption processes. The fact that there are positive gadolinium anomalies means that medical and municipal wastewater are also involved in the environmental pollution from critical elements. Multivariate research revealed certain geochemical groups linked to changes in water flow and land use. These results indicate that rare earth elements are reliable indicators of geological processes and anthropogenic pollution. This made it possible to study the sediments in urban rivers as archive of how the climate has changed and how people have affected it over the Anthropocene. The results showed how important pollution control policies and climate change efforts are for directly dealing with health problems in the area and safeguarding ecosystems.
Key words Climate Rare earth Elements Sediment Pollution Urban setting Multivariate Enrichment