I was very intrigued this week to see new evidence for a controversial theory that combines a wayward comet, the extinction of most Ice-Age creatures, the quick demise of the Clovis culture—and now the strange things that Hopewell people buried in the ground in Ohio some 2,000 years ago.

The controversial theory is largely the brainchild of three American researchers—prominent oceanographer Jim Kennett, nuclear chemist Richard Firestone, and geophysicist Allen West. In essence, the theory suggests that an errant comet swung into Earth’s atmosphere some 12,900 years ago, fractured into pieces and exploded over northern Ontario. The resulting aerial firestorms then set much of North America ablaze, wiping out mastodons, giant grounds and other Ice-Age fauna, and devastating bands of Clovis hunters. At least that’s the theory.

Last year, Kennett and his colleagues published provocative evidence to support these contentions. Samples taken from eight Clovis-era sites revealed, for example, a narrow, 12,900-year-old layer rich in carbon and studded with extraterrestrial material such as nanodiamonds. This, they suggested, held the debris of the comet.

Now, Ken Tankersley, a University of Cincinnati geoarchaeologist and former comet-theory skeptic, has added a new line of evidence. Tankersley has been looking at the Hopewell people, who built many of the great earthen mound complexes in Ohio. The Hopewell were collectors par excellence, whose taste for rare and beautiful things reminds me sometimes of the European princes who built wonder-rooms or cabinets of curiosities in their castles. The Hopewell collected everything from meteoric iron and mica sheets to fossil ivory and fossil shark teeth, then they turned these objects into ritual offerings.

Tankersley and others have long wondered where the Hopewell got some of this stuff, particularly the chunks of heavy minerals—such as gold, silver and copper—and the diamonds unearthed at the Turner Site in Ohio. Everyone long assumed that the ancient mound-builders obtained them through long-distance trade some 2,000 years ago. But a new study led by Tankersley now shows that these minerals came from late Ice Age deposits located next to the Turner site. The trouble is that glacial ice didn’t carry these unusual deposits all the way from northern Ontario, so how did these minerals get to Ohio more than 10,000 years ago?

Consider the possibility of a comet. New tests by University of Cincinnati geologist Warren Huff show that the mysterious Ohio deposits originated in the diamond fields region of northern Ontario. Perhaps there is still a very good terrestrial explanation for this. But extraterrestrial theorists have leapt on this new evidence, suggesting that an exploding comet hurled the diamond-riddled rock of Ontario hundreds of miles southward 12,900 years ago.

Moreover the new find has convinced Tankersley, a researcher with a reputation for caution, that there is real substance in this comet theory. It’s a very interesting development.

This entry was posted by Heather Pringle on Friday, July 18, 2008. Discussion of this blog entry is now closed.

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