DID A COMET CAUSE A FIRESTORM THAT DEVESTATED NORTH AMERICA 12,900 YEARS AGO?

Since no large impact site has yet been found, Arizona-based geophysicist and team member Allen West, likewise offers the solution that the object was ‘a low density object’, i.e. a comet that fragmented into many pieces as it entered the atmosphere, causing a series of ‘massive aerial explosions’, each one similar to what happened in Tunguska back in 1908, which spread gradually southwards.

So far no epicentre for the proposed cataclysm has been determined, though the geologists are currently searching in the north of the North American continent, where some of the highest levels of extraterrestrial material have been found. This includes an archaeological site at Gainey in Michigan, which in 12,900 BP lay just beyond the southernmost reach of North American’s primary ice sheet as it receded around the end of the last Ice Age.

Levels of extraterrestrial debris seem to decease further south, suggesting that the comet might well have blown up over Ontario or the Hudson Bay area. Geologists believe that the Great Lakes could well provide vital clues of the catastrophe. Team member Richard Firestone has detected ‘four large holes in the lakes which deeper than Death Valley, so we kind of suspect that pieces of this impact did penetrate them.’ A 400-kilometre long anomaly in the Hudson Bay is also being investigated as a possible rim of a giant impact crater. Yet if the comet did approach from the north or northwest, then it is likely that the largest and heaviest fragments reached further that suspected impact craters such as the Carolina Bays, meaning that marine geologists should be searching beyond their extent in the West Atlantic Basin (a subject also dealt with below).

Another possibility is that the main impact crater was created in the hundreds of metres thick ice sheet north of Michigan, which would have disintegrated, leaving relatively few traces, when finally the ice melted, bringing an end to the last Ice Age.