Comet Crushed Clovis Culture?

There is something oddly compelling about doomsday scenarios in which an asteroid or comet tumbles to earth and destroys an entire civilization. Maybe it is the religious element or the “hero that saves the world” drama we see in movies (there are a lot of flicks out there).

So what better place to discuss a sexy topic like this than the beach paradise of Acapulco?



This week, geologists will convene at the American Geophysical Union’s Joint Meeting in Acapulco to discuss a controversial new theory: that an extraterrestrial impact, possibly a comet, impacted North America nearly 13,000 years ago, setting off a 1,000-year-long cold spell and wiping out entire species.

The BBC summarizes the evidence:

The evidence comes from layers of sediment at more than 20 sites across North America.

These sediments contain exotic materials: tiny spheres of glass and carbon, ultra-small specks of diamond – called nanodiamond – and amounts of the rare element iridium that are too high to have come from Earth.

All, they argue, point to the explosion 12,900 years ago of an extraterrestrial object up to 5km across.

No crater remains, possibly because the Laurentide Ice Sheet, which blanketed thousands of sq km of North America during the last Ice Age, was thick enough to mask the impact.

Another possibility is that it exploded in the air.

Researchers have for some time proposed that a reversal in the world’s ocean currents and a corresponding global cooling was responsible for the rapid geological change that led to the extinction of multiple species of animals and the end of the Clovis Culture. A comet could explain the shift:

According to the new idea, the comet would have caused widespread melting of the North American ice sheet. The waters would have poured into the Atlantic, disrupting its currents. This, they say, could have caused the 1,000 year-long Younger Dryas cold spell, which also affected Asia and Europe.

This geological rap session may be just sexy enough to keep the scientists from laying on the beach all-day.