Trace 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), were 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). Samples 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 2% HNO3 for trace metals analysis by Sector Field Inductively Coupled Mass Spectrometry (SF-ICP-MS, Thermo Fisher Scientific, Bremen, Germany) at the Central Science Laboratory (UTAS, Hobart, Australia). Indium was added as internal standard (In, 100 ppb). 88Sr, 89Y, 95Mo, 107Ag, 109Ag, 111Cd, 133Cs, 137Ba, 146Nd, 169Tm, 171Yb, 185Re, 187Re, 205Tl, 208Pb, 232Th, 238U, 23Na, 24Mg, 27Al, 31P, 32S, 42Ca, 47Ti, 51V, 52Cr, 55Mn, 56Fe, 59Co, 60Ni, 63Cu and 66Zn were analysed using multiple spectral resolutions. Element quantification was performed via external calibration using multi-element calibration solutions (MISA suite, QCD Analysts, Spring Lake, NJ, USA). Raw intensities were blank and dilution corrected. ReferencesArmand, 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 PublicationsHuang, 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), 383.2017年1月14日至3月5日，研究团队搭乘澳大利亚海洋国家设施“调查者号”（R/V Investigator）科考船，于东南极大陆边缘采集了沉积岩芯，对应航次编号为IN2017_V01（Armand等，2018）。本次以“萨布丽娜海底调查”（Sabrina Sea Floor Survey）命名的海洋地球科学考察，核心研究内容为托滕冰川（Totten Glacier）与南大洋（Southern Ocean）在多个冰期旋回中的相互作用。 研究团队使用多管取样器（multi-corer, MC）采集岩芯，将岩芯以1厘米为间隔进行切片，装入聚乙烯塑料袋后冷藏保存。将样品运回位于澳大利亚霍巴特的塔斯马尼亚大学海洋与南极研究所（IMAS, UTAS）后，先在40℃鼓风烘箱中烘干沉积物样品。称取300mg干燥沉积物，与12mL还原溶液（0.005M盐酸羟胺（hydroxylamine hydrochloride, HH）/1.5%乙酸（acetic acid, AA）/0.001M乙二胺四乙酸钠（Na-EDTA）/0.033M氢氧化钠（NaOH），pH=4）混合，以涡旋振荡10秒实现均质化（Huang等，2021）。 为彻底去除沉积物中的氧化物与过剩矿物以分离碎屑组分，随后使用15mL 0.02M HH/25% AA溶液进行第二次浸提，以转速20rpm的旋转摇床振荡过夜（Wilson等，2018）。完成浸提后对样品进行离心处理，用Milli-Q超纯水冲洗3次，再置于50℃鼓风烘箱中烘干。 称取约50mg得到的干燥碎屑沉积物，研磨后装入聚四氟乙烯（Teflon）消解罐中，采用强酸混合体系进行分步消解：首先使用浓硝酸（HNO₃）与30%过氧化氢（H₂O₂）按1:1体积比混合的溶液氧化样品；随后在敞口消解罐中加入10mL硝酸、4mL盐酸（HCl）与2mL氢氟酸（HF），在180℃下加热至样品近干；将消解残渣转移至硝酸体系后，加入1mL硝酸与1mL高氯酸（HClO₄）的混合液，在220℃下加热至完全蒸干；最后用4mL 7.5M硝酸将消解后的样品重新溶解。 从4mL的消解母液中移取400μL等分试样，用2%硝酸溶液稀释约2500倍，采用扇形磁场电感耦合等离子体质谱仪（Sector Field Inductively Coupled Mass Spectrometry, SF-ICP-MS，赛默飞世尔科技，德国不来梅），于塔斯马尼亚大学中央科学实验室（UTAS, 霍巴特，澳大利亚）开展痕量金属分析。分析过程中加入铟（In，100ppb）作为内标元素。 本次检测的元素包括⁸⁸Sr、⁸⁹Y、⁹⁵Mo、¹⁰⁷Ag、¹⁰⁹Ag、¹¹¹Cd、¹³³Cs、¹³⁷Ba、¹⁴⁶Nd、¹⁶⁹Tm、¹⁷¹Yb、¹⁸⁵Re、¹⁸⁷Re、²⁰⁵Tl、²⁰⁸Pb、²³²Th、²³⁸U、²³Na、²⁴Mg、²⁷Al、³¹P、³²S、⁴²Ca、⁴⁷Ti、⁵¹V、⁵²Cr、⁵⁵Mn、⁵⁶Fe、⁵⁹Co、⁶⁰Ni、⁶³Cu与⁶⁶Zn，采用多种光谱分辨率进行检测。 元素定量通过多元素校准溶液（MISA系列，QCD Analysts公司，美国新泽西州斯普林湖）建立外标曲线完成。原始计数强度数据需经过空白校正与稀释倍数校正。 参考文献： 1. Armand, L. K., O’Brien, P. E., Armbrecht, L., Baker, H., Caburlotto, A., Connell, T., … Young, A. (2018). 托滕冰川与南大洋在多个冰期旋回中的相互作用（IN2017-V01）：航后报告. 澳大利亚国立大学研究出版物（ANU Research Publications） 2. Huang, H., Gutjahr, M., Kuhn, G., Hathorne, E. C., and Eisenhauer, A. (2021). 南大洋沉积物中过去海水铅与钕同位素信号的高效提取. 《地球化学、地球物理学、地球系统》, 22(3), 1–22. 3. Wilson, D. J., Bertram, R. A., Needham, E. F., van de Flierdt, T., Welsh, K. J., McKay, R. M., … Escutia, C. (2018). 晚更新世间冰期东南极冰盖的冰量损失. 《自然》, 561(7723), 383.