Fluoride Action Network

Trapped volcanic gases – WSU research gives insight into mass extinction

Source: WSU News (Washington State University) | WSU science writer
Posted on January 10th, 2012
Industry type: Volcanoes

PULLMAN, Wash. – A Washington State University researcher’s analysis of gases trapped in microscopic, 250 million-year-old crystals is adding new insights to a theory that volcanic activity led to the world’s largest known extinction.

Michael Rowe, a volcanic geochemist and research associate in the School of the Environment, was part of a study that found high quantities of chlorine, fluorine and sulfur in massive flood basalts that spread across what is now Siberia. The researchers found the concentrations of these gases were substantially higher than those of other flood basalts, including those across Eastern Washington, indicating a drastic reduction of environmental quality across the planet.

Researchers need to look more closely at eruption rates and model how the gases would have interacted with the atmosphere and life forms of the era. But the presence of so much potentially toxic gas fuels the theory that the Siberian Traps caused the Permian period’s mass extinction. Also known as the Great Dying, the event wiped out nearly all of Earth’s marine species and more than two-thirds of its terrestrial vertebrates.

The term “traps” is derived from the Swedish word for stairs (trappa, or sometimes trapp), referring to the step-like hills forming the landscape of the region.

“We really have expanded our knowledge about the different types or species of gases that could have been injected into the atmosphere,” said Rowe.

The study results are in the Feb. 1 issue of the journal Earth and Planetary Science Letters. Benjamin Black, a Massachusetts Institute of Technology graduate student and lead author of the paper, said Rowe “was really instrumental in the methods” used to calculate the gas concentrations in the Siberian basalts.

Rowe’s research looks at dissolved gases trapped in crystals that form as magma cools and hardens.

“You basically get a little snapshot in time of the magma,” he said.

In the recent study, his main focus was on analyzing concentrations of sulfur and training Black in how to prepare and analyze the samples.

Michael Rowe, Washington State University School of the Environment, 509-335-6770, mcrowe@wsu.edu
Eric Sorensen, Science Writer, Washington State University, 509-335-4846, eric.sorensen@wsu.edu