The XRF and Hm/Gt data from the IODP U1422 borehole in the Japan Sea

For this study, samples from the interval above 45.2 m (base of the Jaramillo subchron) in borehole U1422C were collected at 10 cm resolution. Based on the sedimentation rate of ~4.2 cm/kyr derived from the age model for the 0–45.2 m interval, this sampling interval corresponds to a temporal resolution of approximately 2.5 kyr. A total of 474 samples (10 cm sampling resolution) with approximately 10 g of each sample were ground into powder and passed through a 200-mesh sieve.The IODP U1422 samples were analyzed using a diffuse reflectance spectrophotometer capable of measuring reflectance across the near-ultraviolet (190–400 nm), visible (400–700 nm), and near-infrared (700–2500 nm) spectral ranges. In this study, the visible light band (400–700 nm) was selected as the focus area due to its sensitivity to iron oxide minerals. A TU1950 UV-VIS spectrophotometer was employed for the analysis of all 474 samples.

本研究采集了U1422C钻孔中45.2米以上（对应哈拉米略亚时底界）地层的样品，采样分辨率为10厘米。基于0–45.2米地层区间年龄模型得出的约4.2厘米/千年的沉积速率，该采样间隔对应的时间分辨率约为2.5千年。共获取474份样品（采样分辨率10厘米），每份样品取约10克，经研磨成粉末后过200目筛。采用可覆盖近紫外（190–400 nm）、可见光（400–700 nm）及近红外（700–2500 nm）光谱波段反射率测量的漫反射分光光度计，对国际大洋发现计划（International Ocean Discovery Program, IODP）U1422C钻孔样品进行分析。本研究选取可见光波段（400–700 nm）作为重点分析区间，因其对氧化铁矿物具有较高的敏感性。使用TU1950型紫外-可见分光光度计完成全部474份样品的分析工作。