This study reveals how rare earth elements and yttrium (REY) cycle through an ocean margin system, clarifying the mechanisms that govern benthic REY fluxes and the preservation of Nd isotope compositions (εNd) in authigenic sediment phases.Samples were collected during cruise M182 in 2022. Seawater samples were taken with NISKIN bottles attached to a CTD water sampling carousel or a towed X-tended Ocean Floor Observation System (XOFOS). Samples were filtered using 0.8/0.2 µm Acropak capsule filters. Pore waters were sampled and pooled from several MUC liners. MUC supernatant bottom water, the 0-4 cm layer and 4-25 cm layer were sampled and pooled. Sediments were centrifuged and the supernatant (i.e., the pore water) and the MUC bottom water were filtered through 0.2 µm polyethersulfone (PES) syringe filters. Water samples were preserved by acidification to ~ pH 2 with concentrated distilled HCl.Neodymium was purified using first BIORAD AG50W-X8 resin, followed by Eichrom Ln-spec resin. Samples were measured by MC-ICP-MS.