
Researchers at Ohio State University have discovered that volcanoes played a pivotal role in a deadly ice age that occurred nearly half a billion years ago. This photograph shows volcanic ash beds - formed around 455 million years ago - layered in the rock of the Nashville Dome area in central Tennessee.
The discovery underscores the importance of carbon in Earth's climate today, said Matthew Saltzman, associate professor of earth sciences at Ohio State University.
The results will appear in the journal Geology, in a paper now available online.
Previously, Saltzman and his team linked this same ice age to the rise of the Appalachian Mountains. As the exposed rock weathered, chemical reactions pulled carbon from Earth's atmosphere, causing a global cooling which ultimately killed two-thirds of all species on the planet.