Extinctions: Bad Genes or Bad Luck? Massive eruptions (Introduction)

by David Turell , Saturday, August 29, 2015, 00:16 (3166 days ago) @ David Turell

For the extinction about 250 million years ago, volcanoes:-http://www.livescience.com/52017-catastrophic-volcanoes-caused-biggest-tinction.html?cmpid=NL_LS_weekly_2015-08-28-"Geologists hauling hundreds of pounds of 250-million-year-old rocks from Siberia, through Russian and American customs, say luck was on their side. Not only did they successfully transport the huge haul, but they also may have confirmed the cause of Earth's worst mass extinction.-"The culprit? Catastrophic volcanic eruptions that spewed enough lava to cover Australia led to the die-off at the end of the Permian era, the researchers found. That die-off occurred about 250 million years ago and was the greatest mass extinction in Earth's history; 90 percent of marine species and 75 percent of land dwellers were wiped off the face of the planet over the course of about 60,000 years.-"Ancient volcanic rocks now provide the best evidence yet that catastrophic volcanic activity triggered the extinction, researchers say.-****-"Scientists knew that a key factor behind this disaster may have been one of the biggest continental volcanic eruptions on record. It occurred in what is now Siberia, currently called the Siberian Traps, and spewed out as much as 2.7 million square miles (7 million square kilometers) of lava. This magmatism, or movement of magma, may have injected massive amounts of global warming gases into the atmosphere, wreaking havoc on the environment. These eruptions also led to acid rain that may at times have made the ground as acidic as lemon juice."