Dynamic ocean redox conditions during the end-Triassic mass extinction: Evidence from pyrite framboids

The end-Triassic (?201 Mya) records one of the five largest mass extinction events Phanerozoic. Extinction losses were coincident with large igneous province volcanism in form Central Atlantic Magmatic Province (CAMP) and major carbon isotope excursions (CIEs), suggesting a link between these phenomena. Marine anoxia has been implicated as causal factor crisis, but there remains some uncertainty regarding role marine redox changes phases because both intensity duration are poorly constrained. We employ high resolution pyrite framboid size-frequency analysis at two Triassic-Jurassic (Tr-J) boundary sections: Kuhjoch Austria (the Tr-J Global Boundary Stratotype Section Point; GSSP) St. Audrie's Bay England (former GSSP candidate) order to further evaluate (ETME). section predominantly anoxic conditions punctuated by weakly oxygenated (dysoxic) through transition, even during shallow-water intervals. experienced dysoxic ETME became better near boundary. is therefore locations. A similar history known from European Basin, Western Tethys Panthalassa, where developed lead up prior reoxygenation around