Monday, July 15, 2013

Late Triassic Mass Extinction Shows Common Patterns with the Permian Extinction

Elevated pCO2 leading to Late Triassic extinction, persistent photic zone euxinia, and rising sea levels


1. Caroline M.B. Jaraula (a)
2. Kliti Grice (a)
3. Richard J. Twitchett (b)
4. Michael E. Böttcher (c)
5. Pierre LeMetayer (a)
6. Apratim G. Dastidar (a)
7. L. Felipe Opazo (b)


a. Curtin University, Western Australia Organic and Isotope Geochemistry Centre, Department of Chemistry, Curtin University, Perth, WA 6845, Australia

b. Plymouth University, Geography, Earth and Environmental Sciences, Plymouth PL4 8AA, UK

c. Leibniz Institute for Baltic Sea Research, Geochemistry & Isotope Geochemistry Group, Marine Geology Section, Warnemünde, D-18119 Rostock, Germany


The Late Triassic mass extinction event is the most severe global warming-related crisis to have affected important extant marine groups such as scleractinian corals, and offers potential insights into climate change scenarios. Here we present evidence from Chlorobi-derived biomarkers of episodic and persistent photic zone euxinia. From biomarkers and stable carbon isotopes, we present evidence of rapid mixing of atmospheric and oceanic carbon reservoirs. Global versus regional trends are resolved in kerogen organic matter type, carbonate δ13C, and bulk and pyrite δ34S. This suite of data demonstrates for the first time a comprehensive organic and stable isotope geochemical reconstruction of events leading up to the Late Triassic extinction event and its aftermath. The cascade of events prior to, during, and after the extinction is remarkably similar to those reported for the Late Permian extinction, the largest extinction event of the Phanerozoic. We predict that similar conditions will have occurred during all past episodes of rapid global warming and biotic crisis that are associated with similar rises in pCO2.

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