The Permo-Triassic Extinction

The end of the Permian period 252 million years ago saw the greatest mass extinction in the geological record. Many theories have been advanced as to the cause, including a fall in sea level, severe climate change induced by methane release, intense volcanism, impact by a bolide, overturn of a stratified, sulfidic ocean, or a combination of these. Increasing evidence indicates that the global ocean at this time was anoxic, and likely sulfidic, for a period of time before and through the boundary. Whatever the causes, the extinction event was accompanied by dramatic changes in seawater chemistry including excursions in the isotopic compositions of organic and inorganic carbon.

The aims of this project are to investigate the biomarkers present in well-preserved Late Permian and Early Triassic sediments around the world for clues about changes in ocean chemistry during the extinction period and subsequent radiation. We are particularly interested in measuring the isotopic compositions of specific biomarker molecules that might be informative about primary production and of carotenoids and their derivatives from the green sulfur bacteria.