中国科学院南京地质古生物研究所机构知识库

Carbon isotope compositions of carbonates (delta C-13(carb)) document a new 3.5%. CIE toward lower values concomitant with an Emeishan Large Igneous Province (ELIP)-related drowning event (Mapojiao Event, southern Guizhou) during the early Wuchiapingian. Organic carbon isotope data (delta C-13(org)) have a 2 parts per thousand shift toward higher values across the drowning event, showing decoupling with the delta C-13(carb) evolution. Rock-Eval and palynofacies analyses suggest an elevated flux of terrestrial organic matter (OM) during the drowning episode. Therefore, the decoupling between delta C-13(carb) and delta C-13(org) is best explained by the mixing of different organic carbon pools in the delta C-13(org) curve. Strontium isotope data (Sr-87/Sr-86) also show a transient shift from 0.70715 to 0.70694 associated with this early Wuchiapingian carbon isotope excursion (CIE), which is superimposed on the late Permian prolonged global rising trend. This short-lived Sr-87/Sr-86 excursion is best interpreted as an enhanced hydrothermal flux related to a short pulse of ELIP-related volcanism.