freshare.net
Tiny particles of diamond dust dating back 12,900 years ago have been discovered at six North American sites, including one in the Ozarks. The scientific team that made the discovery says the presence of the diamonds provides strong evidence of an Earth impact with a rare swarm of carbon and water rich comets.
The nanodiamonds, weighing in at just 10 to 2,700 parts per billion, can be produced under high pressure, high temperature conditions and have been discovered in meteorites. The nanodiamonds found in North America were discovered concentrated in similarly aged sediments in Bull Creek, Oklahoma (near Vinita) as well as in Murray Springs, Arizona, Gainey, Michigan, Topper, South Carolina, Lake Hind, Manitoba and Chobot, Alberta.
“These discoveries provide strong evidence for a cosmic impact event at approximately 12,900 years ago that would have had enormous environmental consequences for plants, animals and humans across North America,” said University of Oregon archaeologist Douglas J. Kennett, who was a member of the original research team.
Scientists speculate that this cosmic impact may have been the event that led to the extinction of a large number of animal species, including mammoths. They also belive the event may have affected prehistoric humans known as the Clovis culture, which is considered to have run between 13,200 and 12,900 years ago.