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.