Jiang, LianLianJiangAusín, BlancaBlancaAusínKhanolkar, SonalSonalKhanolkarWang, YunpengYunpengWangGeorge, Simon C.Simon C.George2025-08-312025-08-312024-09-1510.1016/j.palaeo.2024.1123682-s2.0-85198602449https://d8.irins.org/handle/IITG2025/28739Little is known about the Paleocene in the southern Pacific Ocean due to scarce marine records. Here, we present a systematic geochemical investigation using biomarkers, carbonate content, and carbon isotopes of a set of early Paleocene deep-sea cores from International Ocean Discovery Program Expedition 378 Site U1553. The results provide a new Paleocene biomarker profile for the Campbell Plateau, New Zealand. The occurrence and distribution of a series of hopenes, ββ hopanes, sterenes and biomarker-based maturity parameters indicate that these organically-lean sediments are in an early diagenetic stage, with an equivalent vitrinite reflectance of approximately 0.4%. Biomarker data (e.g., gammacerane index and homohopane index), carbonate carbon isotopes (−27.9 ‰ to +2.0 ‰) combined with onboard data (sulphur and methane contents) indicate that the redox properties of the Paleocene southern Pacific Ocean changed from an oxidising-anoxic transition zone to a more reducing marine environment (water depth > 1000 m). The sources of the organic matter are diverse, including algae, bacteria, diatoms, dinoflagellates, and higher plants, but are dominated by aquatic organisms. Our new biomarker record bridges a Paleocene biosphere knowledge gap in the high latitude South Pacific.trueExpedition 378 | Hopanoid | International Ocean Discovery Program (IODP) | New Zealand | SteroidArticlehttps://doi.org/10.1016/j.palaeo.2024.11236815 September 20242112368arJournal3WOS:001274135400001