Volcanic Warming Eyed in 'Great Dying' [View All]

[seemslikeadream]

Posted on Thu, Jan. 20, 2005

RANDOLPH E. SCHMID
Associated Press

WASHINGTON - An ancient version of global warming may have been to blame for the greatest mass extinction in Earth's history.

In an event known as the "Great Dying," some 250 million years ago, 90 percent of all marine life and nearly three-quarters of land-based plants and animals went extinct.

Scientists have long debated the cause of this calamity - which occurred before the era of dinosaurs - with possibilities including such disasters as meteor impacts.

Researchers led by Peter Ward of the University of Washington now think the answer is global warming caused by volcanic activity. Their findings are reported in Thursday's online edition of the journal Science.

They studied the Karoo Basin of South Africa, using chemical, biological and other evidence to relate layers of sediment there to similar layers in China that previous research has tied to the marine extinction at the same period.
more
http://www.duluthsuperior.com/mld/duluthsuperior/news/politics/10692102.htm