Moderators: MichelleH, Minimalist, JPeters
http://en.wikipedia.org/wiki/Younger_Dryas_impact_eventCharlie Hatchett wrote:
Black Mat at the Murray Springs site, Arizona; the Black Mat covers the Clovis occupation surface
Photo Courtesy of the Center for the Study of the First Americans
The evidence for such an impact event is a layer of unusual materials (magnetic grains, spherules, charcoal, soot, fullerenes, etc.) at the very bottom of the "black mat" of organic material that marks the beginning of the Younger Dryas.
I've never seen anything go from a fringe theory to (almost) accepted fact so fast. You're gonna have to give Arch a good while to get over this.Minimalist wrote:Today's news release:
http://www.newswise.com/articles/view/530208/
“This was a massive continental scale, if not global, event,” Kennett said. He and Erlandson say that they are currently evaluating the existing Paleo-Indian archaeological datasets, which Kennett describes as “suggestive of significant population reduction and fragmentation, but additional work is necessary to test this hypothesis further.” Earlier research efforts need to be re-evaluated using new technologies that can narrow radiocarbon date ranges, and, as funding becomes available, new sites can be located and studied, Erlandson said.
“As we have grown more confident in the theory,” Erlandson said, “we’ve been letting some of it out in informal talks to gage the response to see where we are headed and what the initial objections are, which will help us to maintain our own objectivity.”
BTW, Arch is already having a shit fit over this. Claims it is less plausible than his bible account!
Expect Fundies everywhere to take up the challenge!!
In your neck of the woods, Monk, would have been Ground Zero, according to the researchers. Can you imagine...Minimalist wrote:Probably depended on how close you were to Ground Zero.
Monk, I recommend that you read Firestone's book. Based on what he is outlining the extinctions were rather quick. Many of the megafauna and humans who survived the initial events died within months from radiation complications. Those who lived longer than that had to deal with a ruined environment and many starved to death. Their world turned to crap and the extinctions were likely complete within a year or so.Is there any clues given in the articlesabout how long these extinction events took? One year? Three years? One hundred years?
More on the Acapulco conference.They also found high levels of iridium and titanium, a special form of carbon molecules known as fullerenes that had helium atoms trapped inside, and microscopic diamonds called nanodiamonds. They also found strange rounded carbon grains and glass-like carbon that looks like hardened black taffy. Lots of soot and charcoal are evidence of the ensuing wildfires.
"We really have found the mother lode of impact material," Firestone said.
Above this layer of strange sediment there are no signs of mammoths or many of the other large mammal species of the day, or of the distinctive Clovis points. At many of the sites there is a gap in evidence of humans for several hundred years before new types of spear heads show up.
Just like the mammoths, many of the Clovis people could have been killed by the comet. Those who lived would have struggled to survive once many of the animals they hunted died. The remaining people may have delivered the final blow to the last of the large mammals. These people made it through, and slowly the human population rebounded.
Post-Clovis people were more culturally diverse, as reflected by an array of different spear heads, Kennett said. "This may suggest population fragmentation."
Princeton University paleontologist Gerta Keller studies impacts and is skeptical that the explosion 12,900 years ago was big enough to have had such a big effect on climate and animals.
Keller has found evidence that much larger impacts did not cause any major extinctions. According to her, even the asteroid that left a massive crater on the Yucatan Peninsula known as Chicxulub and is thought to have killed off the dinosaurs did not actually cause their extinction.
"If Chicxulub didn't cause extinctions, then how could something this piddling cause these extinctions, and how could it have changed climate for 1,400 years?" she asked.
Good point.kbs2244 wrote:I still think the elephant in the room that no one is talking about is what this does to the C14 dating process.
Have the labs in that area started factoring all this in?
That one post where he described the effects on the process was dated 2001.
How many old lab reports are going to have to updated, and the implications of the new dates analyzed.
With funding, more then one person has a career here.
Beags, for the new dates on Clovis culture provided by Mike Waters at Texas A&M see:Charlie, the more I read about the effect of the "Comet" on the C14 dating method, the more confused I'm getting. I seem to have trouble grasping all of it.
