In The Field
GSA 2009: Younger Dryas impact criticised again
Posted on behalf of Rex Dalton The fast-sinking idea that a comet struck North America 13,000 years ago, killing off the Clovis Paleo-Indians and triggering the Younger Dryas cold snap, was again undermined by geochemical tests released this week. A US-Belgium team has reported that it can find no evidence of a comet impact at seven sites and in sediments in two ocean cores corresponding to when the object reportedly exploded over the North American ice sheet. Francois Paquay, a doctoral student at the University of Hawaii in Honolulu, reported the team’s results at the annual meeting of the Geological