210-Pb activities data from multi-core 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, allowing to sample the surface of the sediment (top ~ 30cm). The cores were then sliced every centimetre, wrapped up in plastic bags, and stored in the fridge. The sediment samples were dated using 210-Pb analysis for future paleo-reconstructions. 210-Pb is a radioisotope which allows to date sediment back to 150 years, which is ideal for surface (i.e. recent) sediment samples. Sediment samples were dried, ground and sent to Edith Cowan University (Joondalup, Western Australia) for sample preparation and analysis. Total 210Pb was determined through the analysis of its granddaughter 210Po by alpha spectrometry after complete sample digestion using an analytical microwave in the presence of a known amount of 209Po added as a tracer (Sanchez-Cabeza et al., 1998). The concentrations of excess 210Pb were determined as the difference between total 210Pb and 226Ra (supported 210Pb), the later determined by gamma spectrometry through the measurement of its decay products 214Pb and 214Bi using a HPGe detector (CANBERRA, Mod. SAGe Well).ReferencesL.K. Armand, P.E. O’Brien and On-board Scientific Party. 2018. Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report, Research School of Earth Sciences, Australian National University: Canberra.Sanchez-Cabeza J. A., Masqué P. and Ani-Ragolta I. (1998) 210Pb and 210Po analysis in sediments and soils by microwave acid digestion. J. Radioanal. Nucl. Chem. 227, 19–22.

本数据集的沉积物岩芯（sediment cores）采集于东南极陆缘（East Antarctic margin），搭载澳大利亚海洋国家设施“调查者号”（R/V Investigator）科考船，于2017年1月14日至3月5日完成采集，航次编号为IN2017_V01（Armand等，2018）。本次海洋地球科学考察命名为“萨布丽娜海底调查”（Sabrina Sea Floor Survey），核心研究方向为探讨托滕冰川（Totten Glacier）与南大洋在多个冰期旋回中的相互作用。科考采用多管采样器（multi-corer）采集岩芯，可获取沉积物表层约30厘米的样品。采集后的岩芯以每厘米为单位进行切片，封装于塑料袋中并冷藏保存。为开展后续古环境重建工作，本次沉积物样品采用210铅（210-Pb）测年法进行年代学分析。210铅是一种放射性同位素，可对距今150年以内的沉积物进行年代测定，非常适用于表层（即近代）沉积物样品的测年工作。沉积物样品经干燥、研磨后，被送往西澳大利亚州琼达卢普的埃迪斯科文大学（Edith Cowan University）开展样品前处理与分析测试。总210铅的测定方法为：先以已知量的209钋（209Po）作为示踪剂，经微波消解完成样品前处理后，通过分析其衰变子体核素210钋（210Po），采用α能谱法（alpha spectrometry）进行定量（Sanchez-Cabeza等，1998）。过剩210铅的浓度通过总210铅与支撑性210铅（即226镭（226Ra）衰变产生的210铅）的差值计算得到；其中226镭的活度采用高纯锗探测器（HPGe detector，CANBERRA，型号SAGe Well），通过γ能谱法（gamma spectrometry）测定其衰变子体214铅（214Pb）与214铋（214Bi）的活度获得。参考文献：1. L.K. Armand、P.E. O’Brien及科考现场科学工作组. 2018. 多冰期旋回下托滕冰川与南大洋的相互作用（IN2017-V01）：考察后报告. 澳大利亚国立大学地球科学研究学院，堪培拉. 2. Sanchez-Cabeza J. A.、Masqué P.、Ani-Ragolta I. 1998. 微波酸消解-α能谱法测定沉积物与土壤中的210Pb和210Po. 《放射性核素与核化学杂志》（J. Radioanal. Nucl. Chem.），227卷，19–22页.