X-ray diffraction results from IODP Hole 386-M0081E

Results of X-ray diffraction (XRD) 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. During the onshore phase a set of solid-phase samples, with a volume of approx. 10 cubic centimeters each, were taken with the purpose to be later on split into aliquots for the following three analyses: X-ray diffraction, carbon and X-ray fluorescence. The bulk solid-phase samples were taken from the work halves of core sections at about one sample per meter on average. Unprocessed samples were then shipped to the MARUM - Center for Marine Environmental Sciences of the University of Bremen (Germany), where they were freeze-dried, ground and homogenized to a fine powder (<20 µm particle size) by ECORD Science Operator staff using a pestle and an agate mortar. The aliquots for XRD analysis were prepared with the Philips backloading system in the Crystallography and Geomaterials Research laboratories of the Geoscience Department at the University of Bremen (Germany). X-ray diffractograms were measured on a Bruker D8 Discover diffractometer. Mineral identification and semi-quantification were done using the Philips software X'Pert HighScore Version 1.2 (Degen et al., 2014, https://doi.org/10.1017/S0885715614000840) and follows concepts of Vogt (2009, https://doi.org/10.2204/iodp.proc.302.203.2009). Minimum relative errors are given based on Vogt et al., 2002 (https://doi.org/10.1346/000986002760833765). Clay Mineral groups are used as sums of multiple minerals. In many samples there is a bulb below 20-25° 2theta pointing to amorphous SiO2, which can be biogenic (e.g. diatoms etc.) or volcanic glass. The bulb size could implicate about 10-20 wt.% of amorphous SiO2. Exact quantification of this component would require more detailed XRD experiments.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）指定钻孔的X射线衍射（X-ray diffraction, XRD）分析结果。该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，搭载日本调查船“开阳丸”（R/V Kaimei），往返于日本横须贺港；后续陆上作业阶段搭载“地球号”深海钻探船（D/V Chikyu），实施时间为2022年2月14日至2022年3月15日。陆上作业阶段采集了一批固相样品，单样体积约10立方厘米，后续将其拆分为分样，用于三项分析：X射线衍射、碳元素分析以及X射线荧光光谱分析。大块固相样品取自岩心剖面的工作半段，平均采样间距约为每米1个样品。未处理的样品被运送至德国不来梅大学海洋环境科学中心（MARUM - Center for Marine Environmental Sciences of the University of Bremen），由欧洲大洋钻探合作组织科学操作员（ECORD Science Operator）工作人员使用研杵和玛瑙研钵进行冷冻干燥、研磨并均质化处理，最终制成粒径小于20微米的细粉。用于XRD分析的分样采用飞利浦背装样系统，在不来梅大学地球科学系晶体学与地球材料研究实验室完成制备。X射线衍射图谱采用布鲁克D8 Discover衍射仪进行采集。矿物鉴定与半定量分析使用飞利浦X'Pert HighScore 1.2版软件完成（Degen等，2014，https://doi.org/10.1017/S0885715614000840），分析方法遵循Vogt（2009，https://doi.org/10.2204/iodp.proc.302.203.2009）提出的理论框架。相对误差下限基于Vogt等（2002，https://doi.org/10.1346/000986002760833765）的研究确定。黏土矿物组以多种矿物的总和进行统计。多数样品在2θ角20°~25°以下区域存在宽化衍射峰，指示非晶态二氧化硅的存在，该物质可能为生物成因（如硅藻等）或火山玻璃。该宽化峰的强度大致对应约10 wt.%~20 wt.%的非晶态二氧化硅含量。若要精准定量该组分，需开展更细致的XRD实验。更多方法学细节可参见Strasser M.等（2023）的方法章节，https://doi.org/10.14379/iodp.proc.386.102.2023