Interstitial water geochemistry results of IODP Hole 386-M0087B

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. […]

本数据集为国际大洋发现计划（International Ocean Discovery Program, IODP）386航次（日本海沟古地震研究）指定钻孔的间隙水（interstitial water, IW）地球化学分析结果。该航次的海上作业阶段于2021年4月13日至2021年6月1日期间开展，搭载日本科考船“海鸣号”（R/V Kaimei）从日本横须贺出发并返回横须贺；随后的陆上作业阶段于2022年2月14日至2022年3月15日期间在“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立即进行，采用Rhizon采样器获取样品。每个样品从岩芯段中提取约15 mL间隙水，Rhizon采样器的最长滞留时长为6小时。后续将主要间隙水样品拆分为最多7个子样，用于开展国际大洋发现计划标准测试项目：硫化物检测（1.5 mL间隙水 + 0.6 mL 2.5%乙酸锌溶液）、盐度测定（0.5~1.5 mL样品）、pH与碱度测定（3~4 mL样品）、铵离子检测（0.5~1.5 mL样品）、阳离子分析（3 mL间隙水 + 0.03 mL硝酸）以及阴离子分析（3 mL样品）。除岩芯间隙水样品外，还通过连接真空管的杜兰瓶（Duran bottle）与真空泵装置，从触发式岩芯顶部采集底层水（bottom water, BW）样品。[…]