Authigenic Pb and Nd isotope composition snapshot of surface sediments in the Atlantic sector of the Southern Ocean

Radiogenic lead (Pb) and neodymium (Nd) isotope compositions extracted from authigenic phases in marine sediments are sensitive tracers to reconstruct past ocean circulation and water mass mixing. Chemical reductive leaching of hydrogenetic ferromanganese oxyhydroxides from bulk sediments is the most practical way to recover past seawater Pb and Nd isotope signatures in the Southern Ocean, due to the scarcity of alternative archives. However, the leached signal could be compromised if substantial quantities of Pb and Nd were released from non-hydrogenetic sediment fractions during chemical extraction. We developed a very short 10-seconds leaching method to extract reliable seawater Pb and Nd isotope signals from sediments in the Atlantic sector of Southern Ocean. Based on this method, we extracted seawater Pb and Nd signals from 70 core top sediments covering different geological settings in the Atlantic sector of Southern Ocean collected by past Polarstern RV cruises to evaluate factor controlling the regional authigenic Pb and Nd isotopic composition variability.