Lava Flows (IMAGE) Princeton University Caption In the past several years, improved dating technology has allowed geologists to identify three distinct phases of Deccan volcanism. The first and weakest began roughly 67.5 million years ago. The second and largest phase accounted for 80 percent of the total volcanism and produced the largest lava flows in Earth's history (represented by vertical black bars). Princeton researchers found that thisactivity wiped out nearly 100 percent of planktonic foraminifera and ultimately initiated the Cretaceous-Tertiary mass-extinction event. They further reported that a less severe third eruption phase occurred roughly 300,000 years after the mass extinction and kept the Earth nearly uninhabitable for another half-million years. Credit Courtesy of Gerta Keller Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.