Stable Isotopes of Biomarkers in Permian/Triassic Sediments: Searching for Clues to the Cause of the end-Permian Mass Extinction Event

Introduction

The end of the Permian period 251 million years ago saw the greatest mass extinction of animals and plants in the past 600 million years. The mechanism leading to the mass extinction is still an ongoing focus of debate. Development of global anoxia, overturn of stagnant deep ocean waters and themelting of gas hydrates are the mechanisms that are continually invoked. An investigation of molecular fossils (biomarker distributions and measurement of their stable isotopic composition), sulfur isotopes and iron speciation may contribute to a coherent portrayal of the decline, collapse and subsequent recovery of biological species at this major extinction event. This approach is being applied to organic-rich P/Tr sections about the globe in East Greenland, Canada, China, Australia, Tibet-Kashmir and Japan.