These events are also seen as part of the Holocene extinction phenomenon.
One or more big explosions may have occurred above or possibly on the Laurentide Ice Sheet in the region of the Great Lakes.
The impact of this postulated event (or series of events) goes beyond the Americas.
A number of studies reported evidence of this impact around the world. argued for the deposition of impact spherules 12,800 years ago across four continents, including Europe and the Middle East.
The evidence in favour of a meteoric impact initiating the Younger Dryas cooling period includes carbon-rich layers of soil that have been found at some 50 Clovis sites across North America.