(Table S1) Description of two-way traveltimes from different Sites of IODP Exp339

The Contourite Depositional Systems (CDS) in the Gulf of Cádiz and on the West Iberian margin preserve a unique archive of Mediterranean Outflow Water (MOW) variability over the past 5.3 Ma. These CDS have been recently drilled in several places during the IODP Expedition 339. These drill sites now offer a new window to the internal Pliocene and Quaternary architecture of the CDS. In this study, we use downhole and core Gamma Ray (GR) data acquired from 5 sites drilled in the CDS along the middle slope and 1 site drilled in the deeper setting of the lower slope, out of the MOW path. The GR data primarily tracks the clay content in the sediment and is the expression of sediment supply and, for sites drilled in the CDS, of the bottom current processes. Both appear astronomically controlled as shown by spectral analysis performed on the GR data. Results also reveal that the GR log patterns correlate well across the sites over the last 1.4 My. Several GR horizons corresponding to drops in GR values were identified, most of which fit with coarse-grained deposits observed in cores and interpreted as contourite beds. The GR horizons are interpreted as isochronous horizons, providing a regional scale chronostratigraphic framework for the CDS depositional records with an accuracy of ~ 20 ky. We further assess the spatial and temporal variability of the CDS hiatuses at the regional scale.

加的斯湾及伊比利亚西部陆缘的等深流沉积体系（Contourite Depositional Systems, CDS）保存了过去530万年以来地中海流出水（Mediterranean Outflow Water, MOW）变化的独特档案。近期，国际大洋发现计划（International Ocean Discovery Program, IODP）第339次航次在多个站位钻取了此类CDS的岩心，为研究CDS内部的上新世与第四纪结构提供了全新窗口。本研究使用了两类站位的井下与岩心伽马射线（Gamma Ray, GR）数据：一类为沿中陆坡CDS分布的5个钻取站位，另一类为位于MOW路径之外的下陆坡深水区1个钻取站位。GR数据主要反映沉积物中的黏土含量，可表征沉积物供给情况；对于CDS内的钻取站位而言，还可反映底流活动过程。通过对GR数据开展频谱分析可知，上述两类过程均受天文周期调控。研究结果还显示，过去140万年以来，各站位的GR测井曲线形态具有良好的可对比性。研究人员识别出多处对应GR值下降的GR层位，其中绝大多数与岩心中观测到的粗粒沉积（即等深岩层）相吻合。这些GR层位被解释为等时界面，可为CDS沉积记录提供区域尺度的年代地层框架，其精度约为2万年。本研究进一步评估了区域尺度下CDS沉积间断的时空变化特征。