Global continental and marine detrital εNd: An updated compilation for use in understanding marine Nd cycling

• Published in: Chemical Geology
• Main Authors: Robinson, Suzanne, Ivanovic, Ruza, van de Flierdt, Tina, Blanchet, Cécile, Kazuyo, Tachikawa, Martin, Ellen, Cook, Carys, Williams, Trevor, Gregoire, Lauren, Plancherel, Yves, Jeandel, Catherine, Arsouze, Thomas
• Other Authors: University of Leeds, Department of Earth Science and Engineering Imperial College London, Imperial College London, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Florida Gainesville (UF), Texas A&M University College Station, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC-CNS), UK Research & Innovation (UKRI)Natural Environment Research Council (NERC)NE/L002574/1
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Nd isotope composition; Oceanic margins; Sea floor; Database; Benthic flux; GEOTRACES; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Indian; Pacific; Southern Ocean; North Atlantic
• Online Access: https://hal.science/hal-03152871; https://hal.science/hal-03152871/document; https://hal.science/hal-03152871/file/1-s2.0-S0009254121000632-main.pdf; https://doi.org/10.1016/j.chemgeo.2021.120119

International audience Understanding the role of sediment-water interactions in the oceanic cycling of neodymium (Nd) isotopes is essential for its reliable use as a modern and palaeoceanographic tracer of ocean circulation. However, the exact processes that control Nd cycling in the ocean are poorly defined and require an up-to-date knowledge of the sources, sinks and transformation of this tracer to and within the ocean (e.g. as per the GEOTRACES core mission). We propose a considerable improvement of Nd-source identification by providing an extensive and up-to-date compilation of published terrestrial and marine sedimentary Nd isotopic measurements. From this database, we construct high resolution, gridded, global maps that characterise the Nd-isotopic signature of the continental margins and seafloor sediment. Here, we present the database, interpolation methods, and final data products. Consistent with the previous studies that inform our compilation, our global results show unradiogenic detrital Nd isotopic values (εNd ≈ -20) in the North Atlantic, εNd values of ≈ -12 to -7 in the Indian and Southern Ocean, and radiogenic values (εNd ≈ -3 to +4) in the Pacific. The new, high-resolution interpolation is useful for improving conceptual knowledge of Nd sources and sinks and enables the application of isotope-enabled ocean models to understand targeted Nd behaviour in the oceans. Such applications may include: examining the strength and distribution of a possible benthic flux required to reconcile global Nd budgets, establishing the potential use of Nd isotopes as a kinematic tracer of ocean circulation, and a general quantification of the non-conservative sedimentary processes that may contribute to marine Nd cycling.