[Zardoz]

This story describes an interesting theory that maybe a large comet or asteroid exploded in the air above North America 13,000 years ago:

Ice Age blast 'ravaged America'

That would explain the extinctions that occurred at the time, along with the climatic event. Sounds plausible.

[Plantagenet]

Thanks, Zardoz. Thats very interesting.

[basil_hayden]

yeah, that's great, but the geologic record of North Amerca, particularly the Laurentide ice sheet, indicates that deglaciation was happening around 13K ybp....

[Plantagenet]

Thats a tricky time period to determine ages, because (1) there is a plateau in radiocarbon ages, so there isn't much resolution. And (2) the radiocarbon ages have diverged from calendar ages by ca. 1000 years due to changes in the earth's carbon cycle, so that calendar ages are about a thousand years older then radiocarbon ages.

I'm looking forward to learning the details when they come out in a refereed paper soon. The AGU meeting is just the first public unveiling of the idea.

[Kingcoal]

Imagine such an impact today. Peak Oil would no longer be a problem...

[killJOY]

It was my impression that the human critter came & ate 'em.

Like they did everywhere else.

[Twilight]

Who knows? Maybe.

I'll say this though:

Humans with spears >> Large slow land animals with long reproductive cycles.