The 'Younger Dryas impact event' is the name of a
hypothesized impact event at the beginning of the
Younger Dryas cold spell about 10,900
BCE. The impact seems to have occurred near the
North American
Great Lakes; the
bolide may have disintegrated in the air.
Evidence
The evidence for such an impact event is a layer of unusual materials (Nanodiamonds, magnetic grains, carbon spherules, magnetic
spherules, charcoal, soot,
fullerenes enriched in Helium 3, etc.) at the very bottom of the "black mat" of organic material that marks the beginning of the Younger Dryas.
[1]
It is hypothesized that this impact event brought about the extinction of many North American large mammals. These animals included
camels,
mammoths, the
short-faced bear and numerous other species. The markers for the impact event also appear at the end of the
Clovis culture.
2007 AGU Meeting
On
May 24,
2007, a session at the spring 2007 joint assembly of the
American Geophysical Union in Acapulco, Mexico was held to discuss this hypothesis and reveal the evidence.
[ Session Information, 2007 Joint Assembly, Paleoceanography and Paleoclimatology Includes links to abstracts.]
See also
Video of the AGU Press Conference announcing the discovery
★
Pleistocene megafauna
★
Holocene extinction event
References
1. Archaeology: Blast in the past?, , Rex, Dalton, Nature, News article in ''Nature''