The 5th International Conference of Geobiology

The Late Triassic–Early Jurassic transition (~201 Ma) was marked by one of the “Big Five” Phanerozoic mass extinction events, the end–Triassic mass extinction, which was likely driven by massive carbon emissions associated with the emplacement of the Central Atlantic Magmatic Province (CAMP). These emissions are thought to have led to a substantial increase in atmospheric pCO₂ levels. In this study, we present a 6 Myr pCO₂ record spanning the latest Triassic (Rhaetian) to Early Jurassic (Hettangian–Sinemurian), based on high-resolution δ¹³C data of terrestrial organic matter and C₃ plants from northwestern China, the Polish Basin, and the Newark–Hartford Basin. Our C₃ plant-derived results indicate pCO₂ reached 2515 ± 1296 ppmv before the onset of nCIEs at 201.54 Ma, with sporadic peaks up to ~7900 ppmv shortly thereafter. Bulk organic matter data reveal similarly sporadic CO₂ peaks around the Triassic–Jurassic boundary; however, the overall bulk OM-derived trend remains relatively muted, suggesting significant heterogeneity in the carbon cycle response and highlighting uncertainties in the magnitude and persistence of elevated CO₂ conditions.