Two University of Oregon researchers proposed a startling new theory: that an extraterrestrial impact, possibly a comet, set off a 1,000-year-long cold spell and wiped out or fragmented the prehistoric Clovis culture and a variety of animal genera across North America almost 13,000 years ago.

Driving the theory is a carbon-rich layer of soil that has been found, but not definitively explained, at some 50 Clovis-age sites in North America that date to the onset of a cooling period known as the Younger Dryas Event. The sites include several on the Channel Island off California where UO archaeologists Douglas J. Kennett and Jon M. Erlandson have conducted research.

The theory is being discussed publicly, for the first time, in a news conference at the 2007 Joint Assembly of the American Geophysical Union being held in Acapulco, Mexico. Kennett is among the attendees who will be available to discuss the theory with their peers. The British journal Nature addressed the theory in a news-section story in its May 18 issue. Read the rest of this entry »