MULTIPLE S-ISOTOPIC CONSTRAINTS ON ENVIRONMENTAL CHANGES ASSOCIATED WITH THE PERMIAN-TRIASSIC BIOTIC CRISIS

It is widely accepted that paleoceanographic changes play important roles in driving the end-Permian mass extinction as well as the subsequent delayed biotic recovery. To understand the paleoceanographic changes associated with the biotic crisis, we recently analyzed all four sulfur isotopes (32S, 33S, 34S, 36S) of pyrites from the GSSP Meishan section. We discovered the episodic occurrence of negative d34S and negative D33S for the latest Permian sedimentary rocks that may be linked to a near shutdown of bioturbation. We argue that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. To test and develop this hypothesis, we analyze multiple S-isotopes of pyrites from different depositional facies including the Chuanyan section of marine-terrestrial transitional facies. Integrated with the detailed biostratigraphy, we will discuss the significance of multiple S-isotopic analyses in reconstruction of paleoceanographic changes and their implications for the end-Permian mass extinction as well as the delayed biotic recovery during the Early Triassic.