In a new study published today in the journal Science, researchers say they have confirmed that eruptions large enough to bury the U.S. under 300 feet (91 meters) of lava occurred at the same time that vast numbers of plant and animal species disappeared from the fossil record.

About 201 million years ago, tectonic forces started ripping the supercontinent known as Pangaea apart, said Terrence Blackburn, a geologist at the Carnegie Institution for Science in Washington, D.C., and lead author of the study.

The underlying mantle rock melted, generating these large eruptions, he added.

The rift, which eventually created the Atlantic Ocean basin, happened between sections of Pangaea that would go on to become North America and Africa. (Read