Supplementary Information: The Late Lutetian Thermal Maximum: first record of the deep-sea benthic foraminiferal response in the Tasman Sea (IODP Site U1508)

Here, we provide supplementary information including inorganic and organic geochemistry data, magnetostratigraphy data, foraminifera data, and the age model derived from sediment samples taken from IODP Hole U1508C. At this IODP Hole, from the Tasman Sea, we have documented the Late Lutetian Thermal Maximum (LLTM), a brief warming event in the middle Eocene (41.52 Ma). This is the first record of deep-sea benthic foraminifera changes during the LLTM in the SW Pacific. The event coincides with negative δ13C excursions in bulk sediment (0.47‰) and benthic foraminifera (0.36‰), as well as shifts in foraminiferal species and organic geochemistry. Reduced diversity in benthic foraminiferal assemblages during the event indicates environmental stress, likely due to low oxygen conditions, as suggested by dysoxic taxa. Despite the dominance of calcareous taxa, corrosion-resistant species point to slightly CaCO3-corrosive waters without evident dissolution. We infer a shallower thermocline and increased stratification during the LLTM.本数据集提供补充信息，涵盖从塔斯曼海国际大洋发现计划（International Ocean Discovery Program, IODP）U1508C钻孔采集的沉积物样品所得到的无机地球化学数据、有机地球化学数据、磁地层学数据、有孔虫数据，以及据此构建的年代模型。 依托该IODP钻孔的样品，本研究记录了中始新世（距今41.52 Ma）的短暂升温事件——路特期末期热极大值（Late Lutetian Thermal Maximum, LLTM）。这是西南太平洋区域首次报道的LLTM期间深海底栖有孔虫变化记录。该升温事件与全样沉积物（δ¹³C偏移幅度达0.47‰）及底栖有孔虫（δ¹³C偏移幅度达0.36‰）的碳同位素负偏事件相吻合，同时伴随有孔虫物种组成与有机地球化学特征的显著改变。事件发生期间，底栖有孔虫组合的多样性显著降低，指示当时存在环境胁迫；结合低氧类群的出现，推测该胁迫大概率由低氧环境所引发。尽管钙质类群仍占绝对优势，但耐溶蚀物种的存在表明当时海水处于轻微碳酸钙溶蚀状态，并未出现显著的碳酸钙溶解现象。本研究推断，LLTM期间存在更浅的温跃层以及增强的水体层化作用。