Baseline pore-water nutrients, cations and DIC for sediment core SO268/1_5-1 (MUC-01) during RV SONNE cruise SO268/1 in the CCZ, Pacific Ocean@en

This baseline dataset comprises downcore measurements of pore-water nutrients, cations and DIC for a sediment core (MUC) retrieved in the framework of the European collaborative JPI Oceans MiningImpact project onboard R/V SONNE cruise SO268 in 2019. The scientific work during cruise SO268 was part of the second phase of the MiningImpact project (Environmental impacts and risks of deep-sea mining) and is designed to assess the environmental impacts of deep-sea mining of polymetallic nodules in the Clarion-Clipperton Zone (CCZ) in the Pacific Ocean. The pore water was extracted onboard by rhizon sampling. Pore-water nutrient concentrations (nitrate, nitrite, ammonium, silicic acid, phosphate) were analyzed onboard on freshly extracted pore water upon 3-fold dilution or undiluted (ammonium) using a QuAAtro continuous segmented flow analyzer (Seal Analytical). Major and minor elements were determined on acidified samples (25 µL double sub-boiling distilled concentrated HCl per 1 mL sample) using ICP-AES (iCAP 7400, Thermo Scientific) and DIC was determined on HgCl2-treated pore-water samples using a QuAAtro continuous segmented flow analyzer (Seal Analytical) at the Marine Geochemistry Lab, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven.本基准数据集涵盖2019年德国“松内号”（R/V SONNE）科考船SO268航次期间，于欧洲联合JPI Oceans MiningImpact项目框架下采集的MUC沉积岩芯的岩芯剖面孔隙水营养盐、阳离子及溶解无机碳（Dissolved Inorganic Carbon，DIC）测定数据。该航次的科考工作属于MiningImpact项目第二阶段（深海采矿的环境影响与风险），旨在评估太平洋克拉里昂-克利珀顿区（Clarion-Clipperton Zone，CCZ）多金属结核深海采矿活动的环境影响。孔隙水采用Rhizon采样器在科考船现场完成提取。针对新鲜提取的孔隙水，经3倍稀释后（铵态氮采用未稀释样品），使用QuAAtro连续流动分析仪（Seal Analytical公司）测定其营养盐浓度（涵盖硝酸盐、亚硝酸盐、铵态氮、硅酸及磷酸盐）。常量与微量元素则通过酸化处理后的样品（每1mL样品加入25μL二次亚沸蒸馏浓盐酸），使用电感耦合等离子体原子发射光谱仪（ICP-AES，iCAP 7400，赛默飞世尔科技公司）完成测定；溶解无机碳（DIC）经氯化汞（HgCl2）处理后的孔隙水样品，则由不来梅港亥姆霍兹极地与海洋研究中心阿尔弗雷德·魏格纳研究所海洋地球化学实验室采用QuAAtro连续流动分析仪（Seal Analytical公司）测定。