Fate of particulate copper and zinc isotopes at the Solimoes-Negro river confluence, Amazon Basin, Brazil

摘要

The behaviour and fate of copper (Cu) and zinc (Zn) at river confluences is poorly understood, although chemical and physical processes during mixing of compositionally different tributaries might condition metal availability and fluxes to the ocean. To identify and quantify the effect of such processes in river mixing zones, particulate Cu and Zn isotope signatures (delta(65) Cu-SPM and delta Zn-66(SPM)) were measured along cross sections and vertical profiles at the largest river confluence in the world, the "Encontro das Aguas" mixing zone of the Amazon River, where the organic-rich Negro River meets the sediment-rich Solimoes River.