Ba stable isotope excursions induced by multiple hyperthermal events: A potential new index for transient global warming

During the early Paleogene (59–50 Ma), several short-term global warming events, known as hyperthermal occurred. Negative carbon isotope (δ13C) excursions are a typical proxy for detecting events. recovery from δ13C values returned toward pre-event levels via scavenging lighter C isotopes ocean and sequestrating them within sediments. The biological pump plays key role in this process. Barium (Ba) is nutrient-type element primarily transported water column by barite formed microenvironments associated with decomposition of organic matter, Ba-stable ratio productivity. In study, δ138/134Ba bulk sediment samples Ocean Drilling Program Site 738C southern part Kerguelen–Heard Plateau were analyzed. Although predominantly comprised calcareous chalk corresponding to latest Paleocene Eocene (56–52 Ba ratios reflected mixture carbonate barite. Three negative shifts detected, super-warming event “Paleocene–Eocene Thermal Maximum” at 56 Ma two ETM2 I1. changes during PETM comparable those reported South Atlantic Ocean. commonly recognized, scale was smaller modest events (ETM2 I1). stable highly effective powerful tool reveal response surficial system Earth