Geochemical characterization of a marine sediment core from the Joides Basin, Ross Sea, Antarctica

The chemical fractionation of ten metals (Al, Ti, Cr, Fe, Cd, Cu, Mn, Pb, Zn and Ni) is reported for a marine sediment collected in the Joides Basin, Ross Sea, Antarctica. To evaluate their mobility and availability, the BCR sequential extraction procedure was applied on 11 sections of the sediment. The analyses, performed both by ICP-OES and GF-AAS, highlighted that most of the elements were in the residual phase, showing a strong binding with the matrix and a low availability. The BCR sequential procedure allowed us to have an insight into the chemical properties of the sediment and provided useful information about the redox state of the sediment itself and important indication on the availability and partitioning of different metals. A chemometric treatment was applied on the dataset and it showed a separation between the superficial and the deep sections of the core, the first being more influenced by the presence of Mn and the second by an increase in Al, Ti, Fe, Cr and Pb concentrations.