Sample description and geochemistry collected from Mariana forearc boreholes with the HOG sampler

Sample description and geochemistry collected from Mariana forearc boreholes with the HOG sampler Project Name: Collaborative Research: Collaborative Research: Characterization of Subduction Channel Processes, Borehole Sampling at Active Serpentinite Mud Volcanoes on the Mariana Funding: NSF-OCE-1921654 Susan Lang, Woods Hole Oceanographic InstitutionForearc NSF-OCE-1922671 Geoff Wheat, University of Alaska Fairbanks NSF-OCE-1921361 Jeff Seewald, Woods Hole Oceanographic Institution Permits: Mariana Trench National Wildlife Refuge, U.S. Fish & Wildlife Service, Department of the Interior Permit Number: 12541-22009 Project goals: The overarching goal of the project was to understand the reaction processes that occur at depth during subduction. Boreholes drilled during the recent International Ocean Discovery Program Expedition 366 were targeted to collect pristine fluids. The specific goals of the project were to (1) determine the water-rock reactions that control the chemical composition of deep-sourced fluids ascending from atop a subducting slap (2) identify the processes that regulate the nonbiological formation of methane, and assess its potential metabolic impact (3) characterize the origin and abundance of organic carbon molecules to constrain redox and pH conditions within the subduction channel and shallow subsurface environment and (4) relate the permeability of fluid pathways to seamount structure Samples were collected during a 25 day expedition with a deep-sea submersible. A CORK-Lite was be deployed at three newly cased boreholes: U1492D (Yinazao), U1497D (Fantangisña), and U1496C (Asùt Tesoru). Fluids discharging from these three new boreholes, and a fourth already cased borehole (U1200C, South Chamorro), were collected for inorganic and organic geochemical analysis. Dataset Description: Table 1. Sample Logs. Summary of samples collected by the Hydrothermal Organic Geochemistry (HOG) sampler on R/V Kilo Moana (KM22-14) with ROV Jason, on dives J2_1468 through J2_1478, November 20, 2022 to December 17, 2022. Fluid samples were collected into either 2 L or 11 L kynar bags that were acid washed (10% HCl soak overnight, followed by through rinsing, overnight Milli-Q soak, and further rinsing). Additional samples were collected by filtering fluids in situ through sterivex filters, flat filters loaded with RNA later, or copper tubes used for helium gas sampling. Partway through the expedition, a long tube was added to the intake of the sampler that reached deeper into the borehole. Samples collected after this addition recovered higher purity fluids. N.D. is no data. Table 2. Geochemical Data including pH, alkalinity, hydrolizable amino acids, free amino acids, total acetate, total formate, stable isotopes of dissolved inorganic carbon (δ13C), and stable isotopes of water (δ2H and δ18O).采用热液有机地球化学（HOG）采样器采集的马里亚纳弧前钻孔样品及地球化学数据。 项目名称： 合作研究：俯冲通道过程表征与马里亚纳活动蛇纹岩泥火山钻孔采样 资助方： NSF-OCE-1921654 苏珊·朗（Susan Lang），伍兹霍尔海洋研究所 NSF-OCE-1922671 杰夫·惠特（Geoff Wheat），阿拉斯加费尔班克斯大学 NSF-OCE-1921361 杰夫·西沃尔德（Jeff Seewald），伍兹霍尔海洋研究所 许可信息： 美国内政部鱼类及野生动物管理局马里亚纳海沟国家野生动物保护区，许可编号：12541-22009 项目目标： 本项目的总体目标是阐明俯冲过程中深部发生的反应过程。近期国际大洋发现计划（IODP）366航次所钻取的钻孔，旨在采集未受污染的流体样品。 本项目的具体目标包括：(1) 明确控制从俯冲板块顶部上涌的深部来源流体的化学成分的水岩反应过程；(2) 识别调控甲烷非生物形成的过程，并评估其潜在的代谢影响；(3) 表征有机碳分子的来源与丰度，以约束俯冲通道及浅层地下环境中的氧化还原与pH条件；(4) 建立流体通道渗透率与海山构造之间的关联。 样品采集情况： 本次野外航次为期25天，采用深海潜水器完成样品采集。我们在3个新下入套管的钻孔：U1492D（伊纳扎奥）、U1497D（范坦吉尼亚）、U1496C（阿苏特·特索鲁），部署了CORK-Lite。从这3个新套管钻孔以及第4个已完成套管下入的钻孔（U1200C，南查莫罗）所排放的流体，均被采集用于无机及有机地球化学分析。 数据集描述： 表1 样品日志：2022年11月20日至12月17日，在"R/V Kilo Moana"（基洛·莫阿纳号，航次编号KM22-14）上，搭载"ROV Jason"，通过J2_1468至J2_1478共11次下潜，由热液有机地球化学（HOG）采样器采集的样品汇总。 流体样品被采集至经酸洗处理（经10%盐酸浸泡过夜，随后充分冲洗，再经密理博（Milli-Q）超纯水浸泡过夜，再次冲洗）的2 L或11 L kynar袋中。此外，还通过原位过滤方式采集额外样品：采用sterivex过滤器、加载有RNA later试剂的平板过滤器，或用于氦气采样的铜管。在航次进行过半时，我们在采样器的进气口加装了一根长管，可深入钻孔内部。加装该长管后采集的样品具有更高的流体纯度。N.D.表示无数据。 表2 地球化学数据：涵盖pH值、碱度、可水解氨基酸、游离氨基酸、总乙酸盐、总甲酸盐、溶解无机碳稳定同位素（δ¹³C）以及水的稳定同位素（δ²H和δ¹⁸O）。