Data report: composite section and chronology of IODP Sites 339-U1385 and 397-U1385 based on postcruise XRF analysis

Following International Ocean Discovery Program (IODP) Expedition 397, split archive halves from Site 397-U1385 were analyzed at 1 cm resolution using an Avaatech X-ray fluorescence (XRF) core scanner at the University of Cambridge (United Kingdom).The resulting Ca/Ti profiles were used to revise the composite depth scales of Integrated Ocean Drilling Program Sites 339-U1385 and 397-U1385.Expedition 339 recovered a nearly continuous sediment sequence to 151.5 meters below seafloor (mbsf ) at Site U1385, except for a gap spanning Marine Isotope Stage (MIS) 11/Termination V at 53.06 mbsf.This interval was successfully retrieved during Expedition 397, completing the 1.45 My section.The existing depth scale for Site 339-U1385 was revised to integrate this missing sequence.Using dynamic programming, the Ca/Ti signal from Site 397-U1385 was stretched and compressed to align with the revised depth scale of Site 339-U1385.This alignment enables direct transfer of age models and isotopic records between the two.Below 1.45 Ma (148.83 m core depth below seafloor, Method A [CSF-A], or 176.64 m core composite depth below seafloor [CCSF]), the chronology at Site 397-U1385 is established through benthic oxygen isotope stratigraphy and orbital tuning.The isotope record aligns with Site 339-U1385 for MISs 41-47 and extends to MIS 61, where a hiatus (~1.72-1.87Ma) removed MISs 62-70.Below the hiatus, pronounced precession-driven variations in Ca/Ti serve as the basis for astronomical tuning, extending the chronology to 5.3 Ma.The Site 397-U1385 record provides a near-continuous record of changes in sediment composition at millennial resolution to the base of the Pliocene.