Rare Earth Elements concentrations measured in detrital sediment samples collected during the IN2017-V01 voyage of the RV Investigator

Sediment cores were collected from the East Antarctic margin, aboard the Australian Marine National Facility R/V Investigator from January 14th to March 5th 2017 (IN2017_V01; (Armand et al., 2018). This marine geoscience expedition, named the “Sabrina Sea Floor Survey”, focused notably on studying the interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles. The cores were collected using a multi-corer (MC), sliced every centimetre, wrapped up in plastic bags, and stored in the fridge. 
Back at the home laboratory (IMAS, UTAS, Hobart, Australia), sediment samples were dried in an oven at 40°C. Three hundred mg of dry sediment was then homogenised and vortexed for 10-sec with 12 mL of a reductive solution of 0.005M hydroxylamine hydrochloride (HH) / 1.5% Acetic Acid (AA) / 0.001M Na-EDTA / 0.033M NaOH, at pH 4 (Huang et al., 2021). The sediment was then leached a second time (to ensure the removal of all oxides and excess minerals, i.e. to isolate the detrital fraction) with 15 mL of 0.02M HH, 25% AA solution and agitated using a rotisserie (20 rpm) overnight (Wilson et al., 2018). Sample residues were then centrifuged, rinsed with Milli-Q water 3 times, and dried in an oven at 50°C. About 50 mg of resulting dry (detrital) sediment was ground, weighed into a Teflon vial, and digested with a strong acid mixture.
First, the sediment was oxidized with a mixture of concentrated HNO3 and 30% H2O2 (1:1). Samples were then digested in open vials using 10 mL HNO3, 4 mL HCl, and 2 mL HF, at 180°C until close to dryness. Digested residues were converted to nitric form before being oxidised with a mixture of 1 mL HNO3 and 1 mL HClO4 at 220°C until fully desiccated. Samples were finally re-dissolved in 4 mL 7.5 M HNO3.
A 400 μL aliquot was removed from the 4 mL digest solution and diluted ~2500 times in 1% HNO3 for rare earth elements (REE) analysis by Sector Field Inductively Coupled Mass Spectrometry (SF-ICP-MS, Thermo Fisher Scientific, Bremen, Germany) at the Central Science Laboratory (UTAS, Hobart, Australia). Element quantification was performed via external calibration using multi-element calibration solutions (MISA-5, QCD Analysts, Spring Lake, NJ, USA). Samples were introduced to the instrument using an Aridius® II desolvating nebulizer (CETAC Technologies, USA). The DSN was tuned daily, and oxide formation for a range of test analytes (Ba, Ce, U etc) was always less than 0.05%. Isotopes 137Ba, 139La, 140Ce, 141Pr, 146Nd, 150Nd, 147Sm, 153Eu, 158Gd, 159Tb, 163Dy, 165Ho, 166Eu, 169Tm, 172Yb and 175Lu were monitored in low resolution mode. Raw intensities were blank and dilution corrected. 
References
- Armand, L. K., O’Brien, P. E., Armbrecht, L., Baker, H., Caburlotto, A., Connell, T., … Young, A. (2018).  Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report. ANU Research Publications
- Huang, H., Gutjahr, M., Kuhn, G., Hathorne, E. C., and Eisenhauer, A. (2021). Efficient Extraction of Past Seawater Pb and Nd Isotope Signatures From Southern Ocean Sediments. Geochemistry, Geophysics, Geosystems, 22(3), 1–22. 
- Wilson, D. J., Bertram, R. A., Needham, E. F., van de Flierdt, T., Welsh, K. J., McKay, R. M., … Escutia, C. (2018). Ice loss from the East Antarctic Ice Sheet during late Pleistocene interglacials. Nature, 561(7723), 383.

Tags: AMD, AMD/AU, CEOS, CONTINENT > ANTARCTICA > WILKES LAND, DETRITAL SEDIMENT, EARTH SCIENCE > OCEANS > MARINE SEDIMENTS, EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > SEDIMENT CHEMISTRY, EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > SEDIMENT COMPOSITION, EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > TRACE ELEMENTS, GEOGRAPHIC REGION > POLAR, ICP-MS > Inductively Coupled Plasma Mass Spectrometer, LABORATORY, OCEAN > SOUTHERN OCEAN, RARE EARTH ELEMENTS, RV INVESTIGATOR, SEDIMENT CORERS, SHIPS
Organization: Australian Ocean Data Network