Nd isotope composition obtained on mixed planktonic foraminifera samples from core MD90-917

DOI

Neodymium isotopes were measured on mixed planktonic foraminifera from the washed >150 µm size fraction of the samples. The foraminifera tests were crushed between two glass slides to open chambers and fragments were ultrasonicated for 1 min in MilliQ water before pipetting out the suspended particles to separate the waste. This step was repeated until the water became clear and free of clay. Samples were checked under a binocular microscope to ensure that all sediment particles were removed, before they underwent a weak acid leaching for 5 min in 1 ml 0.001 M HNO3 with ultrasonication. After the cleaning step, samples were transferred into a 1.5 ml tube, soaked in 0.5 ml MilliQ water and dissolved using stepwise 100 µl 0.5 M HNO3 until the dissolution reaction stopped. The dissolved samples were centrifuged, and the supernatant was immediately transferred to Teflon beakers to prevent the leaching of any possible remaining phases. The solutions were then dried using a hotplate for Nd purification.Neodymium was purified using Eichrom TRU-Spec and Ln-Spec resins, following the analytical procedure described in Copard et al. (2010). The 143Nd/144Nd ratios were measured using the ThermoScientific NeptunePlus Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS), hosted at LSCE. For the Nd isotope analyses, sample and standard concentrations were matched at 10 ppb. Mass-dependent fractionation was corrected by normalizing 146Nd/144Nd to 0.7219 and applying an exponential fractionation law. During the analytical sessions, every set of two samples was bracketed by analyses of the La Jolla Nd standard solution, which is characterized by certified values of 0.511858±0.000007. The offset value between the results and the certified values of La Jolla was less than 0.4 epsilon units for all of the analyses presented in this study. The analytical errors reported herein correspond to the external two-sigma standard deviation (based on repeated analyses of the La Jolla standard for the different analytical sessions). The obtained analytical errors ranged from 0.1 to 0.6 epsilon units. The analytical blank values for Nd obtained for the full procedure were <4 pg, which represents less than 0.1% of the minimum Nd yield from foraminifera (around 4 ng) used in this study. As a result, no blank correction was applied.

Identifier
DOI https://doi.org/10.1594/PANGAEA.926908
Related Identifier https://doi.org/10.1594/PANGAEA.926899
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.926908
Provenance
Creator Colin, Christophe ORCID logo; Duhamel, Maxence
Publisher PANGAEA
Publication Year 2021
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Dataset
Format text/tab-separated-values
Size 68 data points
Discipline Earth System Research
Spatial Coverage (17.613 LON, 41.298 LAT); Mediterranean Sea