Interstitial water geochemistry results of IODP Hole 386-M0086A

Results of interstitial water (IW) geochemistry analyses from the above given hole of International Ocean Discovery Program (IODP) Expedition 386 (Japan Trench Paleoseismology). The offshore phase of this expedition took place between 2021-04-13 and 2021-06-01 onboard Japanese R/V Kaimei from and to Yokosuka, Japan, followed by an onshore phase onboard D/V Chikyu between 2022-02-14 – 2022-03-15. Sampling for IW geochemistry took place offshore immediately upon core recovery using Rhizon samplers. A total amount of approximately 15 mL IW per sample were extracted from the core sections over a maximum rhizon retention time of 6 hours. IW main samples were subsequently split into as many as seven fractions for the following IODP standard measurements: sulfide (1.5 mL IW + 0.6 mL ZnAc 2.5%), salinity (0.5–1.5 mL), pH and alkalinity (3–4 mL), ammonium (0.5–1.5 mL), cations (3 mL IW + 0.03 mL HNO3), and anions (3 mL). In addition to IW from the core sections, samples of the bottom water (BW) were collected from the top of the trigger core using a Duran bottle and vacuum pump unit connected by tubes.For further methodological information see methods chapter in Strasser, M. et al., 2023 https://doi.org/10.14379/iodp.proc.386.102.2023

本数据集为国际大洋发现计划（International Ocean Discovery Program, IODP）386航次（日本海沟古地震学研究）指定钻孔的间隙水（interstitial water, IW）地球化学分析成果。本航次海上作业阶段于2021年4月13日至2021年6月1日期间开展，作业船为日本“开明号”（R/V Kaimei），往返航经日本横须贺港；后续陆上作业阶段于2022年2月14日至2022年3月15日在“地球号”（D/V Chikyu）上完成。间隙水地球化学采样于海上岩芯回收后即刻进行，采用Rhizon采样器（Rhizon samplers）取样。在最长6小时的Rhizon采样器滞留时长内，从各岩芯段中提取每份约15 mL的间隙水样品。后续将间隙水主样品拆分为最多7个子样，用于以下IODP标准测试：硫化物（1.5 mL间隙水 + 0.6 mL 2.5%乙酸锌（ZnAc）溶液）、盐度（0.5–1.5 mL）、pH与碱度（3–4 mL）、铵离子（0.5–1.5 mL）、阳离子（3 mL间隙水 + 0.03 mL硝酸（HNO3））以及阴离子（3 mL）。除岩芯段间隙水样品外，还采用连接管路的Duran瓶与真空泵装置，从触发式岩芯顶部采集底层水（bottom water, BW）样品。更多方法学细节请参阅Strasser M.等人2023年发表的相关章节，链接：https://doi.org/10.14379/iodp.proc.386.102.2023