This README.txt file was generated on 20210127 by Suzanne M Robinson ------------------- GENERAL INFORMATION ------------------- 1. TITLE OF DATASET Database and global gridded maps of the epsilon neodymium signature of the continental margins and seafloor presented in "Global continental and marine detrital εNd: an updated compilation for use in understanding marine Nd cycling" 2. AUTHOR INFORMATION Principal Investigator Contact Information Name: SUZANNE M ROBINSON Institution: University of Leeds Email: ee14s2r@leeds.ac.uk ORCID: orcid.org/0000-0003-4035-800X Co-investigator Contact Information Name: Ruza F. Ivanovic Institution: University of Leeds Email: r.ivanovic@leeds.ac.uk ORCID: orcid.org/0000-0002-7805-6018 Co-investigator Contact Information Name: Tina van de Flierdt Institution: Imperial College London Email: tina.vandeflierdt@imperial.ac.uk ORCID: orcid.org/0000-0001-7176-9755 Co-investigator Contact Information Name: Cécile L. Blanchet Institution: GFZ German Research Centre for Geosciences Email: blanchet@gfz-potsdam.de Co-investigator Contact Information Name: Kazuyo Tachikawa Institution: Aix Marseille Univ. Email: kazuyo@cerege.fr Co-investigator Contact Information Name: Ellen E. Martin Institution: University of Florida Email: eemartin@ufl.edu Co-investigator Contact Information Name: Carys Falko Institution: University of Florida Email: caryspfalco@gmail.com Co-investigator Contact Information Name: Trevor Williams Institution: Texas A&M University Email: williams@iodp.tamu.edu Co-investigator Contact Information Name: Lauren J Gregoire Institution: University of Leeds Email: l.j.gregoire@leeds.ac.uk Co-investigator Contact Information Name: Yves Plancherel Institution: Imperial College London Email: y.plancherel@imperial.ac.uk Co-investigator Contact Information Name: Catherine Jeandel Institution: LEGOS, University de Toulouse Email: catherine.jeandel@legos.obs-mip.fr Co-investigator Contact Information Name: Thomas Arsouze Institution: BSC-CNS, Barcelona Email: thomas.arsouze@ensta-paris.fr 3. HOW TO CITE THIS DATASET Please cite the publication in which these data are presented: Suzanne Robinson, Ruza Ivanovic, Tina van de Flierdt, Cécile L. Blanchet, Kazuyo Tachikawa, Ellen E. Martin, Carys Cook (Falko), Trevor Williams, Lauren Gregoire, Yves Plancherel, Catherine Jeandel, Thomas Arsouze (2021): Supplementary: Global continental and marine detrital εNd: an updated compilation for use in understanding marine Nd cycling. Chemical Geology. https://doi.org/10.1016/j.chemgeo.2021.120119 --------------------- DATA & FILE OVERVIEW --------------------- The global gridded maps characterising the εNd of the continental margins and seafloor were generated using QGIS. Full documentation of the methods can be found in Supplementary Information Text S3 and S4 of the publication in which these data are presented. 1. Dataset S1- Continental Contains map of the epsilon Neodymium (εNd) signature of the continental rock surrounding the ocean. To be downloaded as: netCDF4 (gridded data: 0.5° × 0.5° resolution) shapefile (vector data) FILE STRUCTURE {DatasetS1-Continental}.zip Dataset S1- Continental |-Gridded |-continentalEpsilonNd.nc |-VectorShapefile |-continentalEpsilonNd.shp Units are in epsilon neodymium (εNd) where: εNd = ((143Nd/144Nd sample/ 143Nd/144Nd CHUR)-1)*10^4 where CHUR corresponds to the 'bulk earth' standard value of 0.512638 (Jacobsen and Wasserburg, 1980) In the accompanying publication, the continental εNd maps are extended out to the continental margins, we define the extent of this extrapolation as being limited to where sediment thickness >= 1000 m according to GlobSed, a total sediment thickness grid for the world's oceans and marginal seas (Straume et al., 2019: http://earthdynamics.org/data/GlobSed). 2. Dataset S2- Seafloor Contains map of the epsilon Neodymium (εNd) signature of the seafloor. To be downloaded as: netCDF4 (gridded data: 0.5° × 0.5° resolution) shapefile (vector data) FILE STRUCTURE {DatasetS2-Seafloor}.zip Dataset S2- Seafloor |-Gridded |-seafloorEpsilonNd.nc |-VectorShapefile |-seafloorEpsilonNd.shp Units are in epsilon neodymium (εNd) where: εNd = ((143Nd/144Nd sample/ 143Nd/144Nd CHUR)-1)*10^4 where CHUR corresponds to the 'bulk earth' standard value of 0.512638 (Jacobsen and Wasserburg, 1980) 3. Global Sediment Epsilon Nd Contains map of the epsilon Neodymium (εNd) signature of the global sediment-water interface. The final characterisation of global εNd distributions at the sediment-ocean interface proposed in the accompanying publication uses the continental εNd map (Dataset S1) extrapolated to where sediment thickness >= 1000 m (according to GlobSed, a total sediment thickness grid for the world's oceans and marginal seas (Straume et al., 2019: http://earthdynamics.org/data/GlobSed)), and the remaining sediment regions are represented using the seafloor εNd map (Dataset S2). To be downloaded as: netCDF4 (gridded data: 0.5° × 0.5° resolution) FILE STRUCTURE {GlobalSedimentEpsilonNd}.zip GlobalSedimentEpsilonNd |-Gridded |-globalSedimentEpsilon.nc Units are in epsilon neodymium (εNd) where: εNd = ((143Nd/144Nd sample/ 143Nd/144Nd CHUR)-1)*10^4 where CHUR corresponds to the 'bulk earth' standard value of 0.512638 (Jacobsen and Wasserburg, 1980) 4. Table S1- Dataset_Nd_Sr_Global.xlsx Full εNd compilation presented in the accompanying publication. See Tables S3 and S4 for the specific data used for each component of the high resolution, spatially continuous εNd distribution presented here. The εNd database will also be made available on the GFZ data repository (https://dataservices.gfz-potsdam.de/panmetaworks/showshort.php?id=escidoc:4094893). Please contact Cécile Blanchet (blanchet@gfz-potsdam.de) for additional data. 5. Table S2- SouthernOceanDataset.xlsx New Southern Ocean εNd data from the <63 µm fraction of Holocene samples from East Antarctica (see Text S1 and Fig. S1 in Supplementary Information of the accompanying publication for methods and site location). 6. Table S3- ContinentalData.xlsx Continental εNd observations utilised in the spatially continuous continental εNd distribution. For data compilation and filtering see methods section 2 and Supplementary Information Text S2 of the accompanying publication. 7. Table S4- SeafloorData.xlsx Marine detrital and pore water εNd observations utilised in the spatially continuous seafloor sediment εNd representation. For data compilation and filtering see methods section 2 of the accompanying publication. 8. Directory S1- Continental Input files required for the continental εNd interpolation. Full methods and user manual to perform the Nearest Neighbour interpolation of discrete points using QGIS are detailed in Supplementary Information Text S3 and S4. All the discrete εNd measurements used can also be found in Table S3- ContinentalData.xlsx FILE STRUCTURE {DirectoryS1-Continental}.zip |-Directory S1- Continental |-README.txt |-discrete_observations |-continental_database.csv |-lithology |-continental_lithology_original.shp |-continental_lithology_revised.shp |-initial_interpolation |-initial_continental_interpolation.shp |-continental_eNd |-Gridded |-continnetalEpsilonNd.nc |-VectorShapefile |-continentalEpsilonNd.shp 9. Directory S2- Seafloor Input files required for the seafloor εNd interpolation. Full methods and user manual to perform the Nearest Neighbour interpolation of discrete points using QGIS are detailed in Supplementary Information Text S3 and S4. All the discrete εNd measurements used can also be found in Table S4- SeafloorData.xlsx FILE STRUCTURE {Directory S2- Seafloor}.zip |-Directory S2- Seafloor |-README.txt |-discrete_observations |-detrital-porewater_database.csv |-lithology |-seafloor_lithology_original.shp |-seafloor_lithology_revised.shp |-initial_interpolation |-initial_seafloor_interpolation.shp |-seafloor_eNd |-Gridded |-seafloorEpsilonNd.nc |-VectorShapefile |-seafloorEpsilonNd.shp -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. SOFTWARE USED TO PRODUCE THE CONTINENTAL AND SEAFLOOR εNd MAPS The maps were generated using QGIS, a free open-source desktop geographic information system (GIS) application. The Nearest Neighbour Join (NNJoin) plugin was used to perform the interpolation of discrete data points based on nearest neighbour relationships. The NNJoin plugin can be installed directly via the QGIS Plugins Manager. 2. METHODS FOR PRODUCING THE CONTINENTAL AND SEAFLOOR εNd MAPS The methodology for producing the εNd maps can be found in the methods section 2 within the main text of the publication. A user manual for the interpolation methods to produce gridded continental and seafloor εNd representations can be found in the Supplementary information: Text S3 of the associated publication. A detailed description of the expert adjustments made to the initial purely numerical interpolation of the continental and seafloor εNd maps are found in the Supplementary information: Text S4. 3. SOFTWARE-SPECIFIC INFORMATION TO VISUALISE THE DATA The datasets containing the continental and seafloor εNd representation can be downloaded in gridded (netCDF4) or vector (.shp) file format. To visualise the gridded data, this format can be read and plotted using software such as Panoply, Python, Matlab, xconv. To visualise the vector data, shape files can be read by a number of GIS software programs such as ArcGIS and QGIS. It is anticipated these maps will be utilised in numerical models investigating sediment-water interaction and marine Nd cycling. The gridded global datasets are high resolution (0.5°×0.5°). Vector files are provided to enable user groups to regrid the data onto a suited resolution (in the instance of a more regional study).