Multiproxy geochemical analysis of a Panthalassic margin record of the early Toarcian oceanic anoxic event (Toyora area, Japan)

摘要: Abstract The early Toarcian oceanic anoxic event (OAE) was a significant palaeoenvironmental perturbation that led to marked changes in ocean chemistry and climate, which also had long-lasting impact on marine ecosystems. global significance of the has been recognised from widespread occurrence ~ 3–7‰ negative excursion carbon-isotope (δ13C) composition organic inorganic matter terrestrial plant material. This feature is indicative pronounced carbon cycle; an inference further supported by evidence for seawater deoxygenation elevated rates burial. Nevertheless, precise impacts this sections outside Boreal Tethyan realms are uncertain. Here, we present results multiproxy geochemical study expanded record northwest Panthalassa Ocean margin exposed southwest Japan (Toyora area, Yamaguchi prefecture). Our indicate studied succession, enrichment persisted through event, but elemental redox proxies do not support persistent anoxia. Analyses terrigenously derived major trace element abundances coupled with sedimentological observations reveal increase coarse-grained sediment close onset ~− 4‰ δ13Corg, coincident inferred flux. These consistent previously published strengthening hydrological cycling increased runoff occurred contemporaneously abrupt warming at isotope event.