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. […]

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）前述钻孔的X射线衍射（X-ray diffraction, XRD）分析结果。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，搭载日本海洋调查船“开阳丸”（R/V Kaimei），以日本横须贺港为起止港；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”钻探船（D/V Chikyu）上完成。陆上作业阶段中，研究人员采集了单个体积约10立方厘米的固相样品，后续将其拆分为分样，用于X射线衍射、碳元素分析及X射线荧光分析三项测试。大块固相样品取自岩心剖面的工作半片，平均采样密度约为每米1件。未处理的原始样品随后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），由欧洲大洋钻探科学运维团队（ECORD Science Operator）的工作人员使用研钵与玛瑙研杵将样品冻干、研磨并均质化为粒径小于20微米的细粉。用于XRD分析的分样采用飞利浦背装样系统，在德国不来梅大学地球科学系晶体学与地质材料研究实验室完成制备。X射线衍射谱通过布鲁克D8 Discover衍射仪采集测试。矿物鉴定与半定量分析采用飞利浦X'Pert HighScore 1.2版软件完成（Degen等人，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）提出的相关理论框架。最小相对误差的计算依据Vogt等人2002年的研究成果（https://doi.org/10.1346/000986002760833765）。黏土矿物组以多种单矿物的含量总和进行统计。多数样品在2θ角20°至25°以下的衍射区间内存在鼓包状衍射峰，指示非晶态二氧化硅的存在，其成因可分为生物成因（如硅藻等）或火山玻璃成因。该衍射鼓包的规模暗示非晶态二氧化硅含量约为10 wt.%至20 wt.%。若需对该组分进行精确定量，则需开展更为细致的X射线衍射实验。[…]