Channel Islands hold evidence of Clovis-age comets

[L. Coyote]

California's Channel Islands hold evidence of Clovis-age comets
http://www.physorg.com/news167329938.html


A 17-member team has found what may be the smoking gun of a much-debated proposal that a cosmic impact about 12,900 years ago ripped through North America and drove multiple species into extinction.

In a paper appearing online ahead of regular publication in the Proceedings of the National Academy of Sciences, University of Oregon archaeologist Douglas J. Kennett and colleagues from nine institutions and three private research companies report the presence of shock-synthesized hexagonal diamonds in 12,900-year-old sediments on the Northern Channel Islands off the southern California coast.

These tiny diamonds and diamond clusters were buried deeply below four meters of sediment. They date to the end of Clovis -- a Paleoindian culture long thought to be North America's first human inhabitants. The nano-sized diamonds were pulled from Arlington Canyon on the island of Santa Rosa that had once been joined with three other Northern Channel Islands in a landmass known as Santarosae.

The diamonds were found in association with soot, which forms in extremely hot fires, and they suggest associated regional wildfires, based on nearby environmental records.

..............

[xchrom]

1. wow -- it's amazing that they can look for and find

such small pieces of evidence.

and remarkable what that evidence means.

[L. Coyote]

2. Did a comet end Clovis Culture?

WATCH: Time Team America, a new national PBS series.
Watch it Online: http://www.pbs.org/opb/timeteam/

Topper Site Hits PBS
http://www.free-times.com/index.php?cat=1992912064185185&ShowArticle_ID=11011407090863237

BY RON AIKEN

University of South Carolina archaeologist Al Goodyear and the paradigm-shifting finds from his archeological site in Allendale County are getting the star treatment in an hour-long feature on the Topper site tonight (Wed., July 15) on PBS from 8 to 9 p.m.

The program, called Time Team America, is a new national PBS series modeled on a similar long-running program in the U.K. The Topper episode will chronicle the extraordinary finds Goodyear and his team have been making every year since 1998 — among them, mounting evidence that humans were in the Americas 50,000 years ago, or about 40,000 years before the previously accepted date.

[Bigmack]

3. Any connection with the mammoth extinctions?

Seems like the timing of this impact is roughly in line with the extinction of the mammoths.... Ms Bigmack

[semillama]

4. That's one of the arguments

And it makes sense, if you have continent-wide grass fires, then animals that depend on grasslands for food are in serious trouble. Mastodons, which browsed on foliage in woodlands, would have been less effected.

[L. Coyote]

5. Precisely the implication of this discovery/hypothesis.

[GaYellowDawg]

6. It also means...

... that a lot of misanthropes are going to be disappointed at losing a major argument about how eeeeevil mankind is.

[Enthusiast]

7. Something else to consider

If ancient hunters were so effective at eradicating the Mammoth and Mastodons why weren't their relatives the Asian and African elephants also hunted to extinction?

[semillama]

8. Easy. Co-evolution with humans, plus Africa at the time

wouldn't have been as affected by a warming climate in terms of megafauna extinctions. The African and tropical Asian megafauna adapted to hunting by early humans, given them an edge over species which didn't know to be wary of humans. Cool climate specialists, as we are seeing today, are more affected. Add in new hunting pressure by the most devastating predator on the planet, and things go south for a lot of species.

[Enthusiast]

9. I've considered the

co-evolution with humans before. Still. But your's is a good explanation.