Revised composite depth scale and splice analysis using detailed hole-to-hole correlations of high-resolution x-ray fluorescence core scanning for IODP Site 342-U1406

Integrated Ocean Drilling Program (IODP) Expedition 342 recovered exceptional Paleogene to early Neogene sedimentary archives from clay-rich sediments in the northwest Atlantic Ocean. These archives present an opportunity to study Cenozoic climate in a highly sensitive region at often unprecedented resolution. Such studies require continuous records in the depth and time domains. Using records from multiple adjacent drilled holes, intervals within consecutive cores are typically spliced into a single composite record on board the JOIDES Resolution using high-resolution physical property data sets acquired before the cores are split. The highly dynamic nature of the sediment drifts drilled during Expedition 342 and the modest amplitude of variance in the physical property records made it possible to construct only highly tentative initial working splices, which require extensive postcruise follow-up work. Postcruise, high-resolution X-Ray Fluorescence (XRF) core scanning data enabled the construction of a preliminary composite depth scale and splice. Here we present the revised composite depth scale and splice for IODP Site U1406, predominantly constructed using detailed hole-to-hole correlations of revisions of the initial XRF data set, and of newly generated high-resolution XRF data. The revised composite depth scale and splice serve as a reference framework for future research on Site U1406 sediments.

综合大洋钻探计划（Integrated Ocean Drilling Program, IODP）第342次航次从西北大西洋的富黏土沉积物中采集到了优质的古近纪至新近纪早期沉积记录序列。这些记录为在该高敏感区域以通常可达前所未有的分辨率开展新生代气候研究提供了绝佳契机。此类研究需要深度域与时间域上的连续记录。依托多个相邻钻井孔获取的记录，科研人员通常会在岩心拆分前，利用采集得到的高分辨率物性数据集，在“乔迪斯·决心号”（JOIDES Resolution）钻探船上将连续岩心的对应层段拼接为单一复合记录。由于第342次航次钻取的沉积漂移体具有高度动态特性，且物性记录的方差幅度较小，仅能构建出高度试探性的初始工作拼接方案，该方案需开展大量航次后跟进工作。航次结束后，高分辨率X射线荧光（X-Ray Fluorescence, XRF）岩心扫描数据助力构建了初步的复合深度标尺与拼接方案。本文针对IODP U1406站位，呈现了修订后的复合深度标尺与拼接方案，该方案主要通过对初始XRF数据集的修订版本开展详细井间对比，并结合新生成的高分辨率XRF数据完成构建。该修订后的复合深度标尺与拼接方案可作为未来针对U1406站位沉积物开展研究的参考框架。