Findings Provide Strongest Link Yet to Volcanically-Associated Cause for End-Permian Mass Extinction

24 03 2010
This image was created by Kiff and is courtesy of Wikimedia Commons.  It is licensed under the GNU Free Documentation License.

Pangea as scientists believe it appeared at the end of the Permian Period

Research results published Monday in the online journal Proceedings of the National Academy of Sciences (PNAS) provides the strongest association between the mass extinction that occurred at the end of the Permian period and volcanic eruptions (specifically those occurring along the east coast of the United States during the beginning of the breakup of Pangea.

 The authors were Jessica H. Whiteside, Paul E. Olsen, Timothy Eglinton, Michael E. Brookfield, and Raymond N. Sambrotto.

 Following is the abstract for the article

 Abstract

A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date.

For more information, please see the original PNAS journal article at the following URL:
http://www.pnas.org/content/early/2010/03/15/1001706107.full.pdf+html?sid=9cdfecda-f033-4211-958c-db9fdb86a405.

This image is in the public domain because it contains material originally created by the U.S. Geological Survey.

This animation shows the breakup of Pangea, that began at the end of the Permian Period. Volcanic Activity associated with this breakup (particularly in Siberia and the US east coast) is believed to have triggered the largest mass extinction in earth's history.

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