Microbial Blooms Triggered Pyrite Framboid Enrichment and Oxygen Depletion in Carbonate Platforms Immediately After the Latest Permian Extinction

Redox variations across the Permian-Triassic boundary (PTB) have long been debated, especially during proliferation of PTB microbialites. Here, we report redox fluctuations to evaluate links between two based on pyrite framboid analysis from basin platform settings in South China. During end-Permian extinction, abundant framboids indicate a widespread anoxia that was likely direct cause extinction. In earliest Triassic (Hindeodus parvus conodont zone), were absent ramp and shallow, nonmicrobialite sections. contrast, coeval microbialites yield indicative dysoxia. The fact only confined other habitats indicates microbe bloom may stimulated dysoxic watermass triggered growth within aggregates. Thus, not built reducing settings, but instead, microbial caused local, dysoxia shallow oxygenated platforms after