Origin of Earth's atmosphere discovered

COLUMBUS, Ohio, Oct. 29 (UPI) -- U.S. researchers have discovered what might be evidence of the origin of Earth's breathable atmosphere, similar to the planet's current oxygen-rich air.

Ohio State University geologists and colleagues said the study suggested upheavals in the Earth's crust initiated a kind of reverse-greenhouse effect 500 million years ago, cooling the world's oceans, spawning giant plankton blooms and sending a giant burst of oxygen into the atmosphere.

Associate Professor Matthew Saltzman, who led the study, said that oxygen might have helped trigger one of the largest growths of biodiversity in Earth's history.

The findings were reported Sunday in Denver during the annual meeting of the Geological Society of America.