Skip to comments.Diamonds Linked to Quick Cooling Eons Ago
Posted on 01/02/2009 9:02:31 AM PST by Pharmboy
University of Oregon
Scientists found microscopic diamonds in the black layer of rock at Murray Springs in Arizona.
At least once in Earths history, global warming ended quickly, and scientists have long wondered why.
Now researchers are reporting that the abrupt cooling which took place about 12,900 years ago, just as the planet was emerging from an ice age may have been caused by one or more meteors that slammed into North America.
That could explain the extinction of mammoths, saber-tooth tigers and maybe even the first human inhabitants of the Americas, the scientists report in Fridays issue of the journal Science.
The hypothesis has been regarded skeptically, but its advocates now report perhaps more convincing residue of impact: a thin layer of microscopic diamonds found in rocks across America and in Europe.
Were up over 30 sites, as far west as offshore California, as far east as Germany, said Allen West, a retired geology consultant who is one of the scientists working on the research.
The meteors would have been smaller than the six-mile-wide meteor that struck the Yucatán peninsula 65 million years ago and led to the mass extinctions of the dinosaurs. The killing effects of the hypothesized bombardment 12,900 years ago would have been more subtle.
Climatologists believe that the direct cause of the 1,300-year cold spell, known as the Younger Dryas, was a sudden rush of fresh water from a giant lake in central Canada to the North Atlantic.
Usually a surface current of warm water flows northward in the Atlantic toward Greenland and Europe, then cools and sinks, returning south in the deep ocean. But the fresh water, which is less dense, blocked the sinking of the cold, salty water in the North Atlantic, disrupting the currents.
(Excerpt) Read more at nytimes.com ...
Global cooling ping...
Diamonds...They don’t call them “ice” for nothin’.
Another bit of “inconvenient” evidence to suggest Gore’s theories on global warming are a pile o crap.
Small crystals equal rapid cooling, large crystals equal slow cooling.
Sience class wasn’t a total waste.
Isn’t this an incorrect usage of the term eon? I thought an eon was composed of more than one geological age...
Well, it is the NYT, so I guess I should not expect much.
It's well known that a meteorite colliding with Earth is considered the most likely reason dinosaurs died off 65 million years ago. Now a team of scientists says it has found new evidence that a comet triggered a similar extinction much more recently: just 13,000 years ago, when humans were around to witness the event and suffer its terrible consequences.
The researchers think the comet exploded above the planet's surface, ultimately killing off mammoths, saber-toothed tigers and other large mammals that roamed North America.
The scientists, led by University of Oregon anthropologist Douglas Kennett, say their report offers up a "smoking bullet" proof that a comet set off the sudden, thousand-year freeze and wiped out the big animals of the era.
Diamonds are forever...
How can "less dense" fresh water block the sinking of cold, salty water? Higher density fluids sink relative to other fluids. Is this New York Slimes science, or am I missing something?
Actually, the microscopic diamonds are a result of a meteor impact, not due to cooling. Impact-type microdiamonds can be used as one indicator of impact craters.
That sentence stopped me also. Perhaps the high-riding, less dense fresh water disrupted the salt water cycling...
Thought that heat and pressure made diamonds ... a diamond is nothing but a lump of coal that stuck with it
The theory goes that all of the fresh water diluted the denser “salt” water turning the Atlantic into more or less of a giant still lake.
Eh, as good a theory as any I guess.
That may be. However, as we are talking about an article in the NY Slimes, there's no guarantee of common sense or accuracy.
Scientists find signs of 13,000-year-old extinction event
Chicago Tribune | January 2, 2009 | Robert Mitchum
Posted on 01/01/2009 2:09:17 PM PST by neverdem
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
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Just adding to the catalog, not sending a general distribution.
· Discover · Nat Geographic · Texas AM Anthro News · Yahoo Anthro & Archaeo ·
· The Archaeology Channel · Excerpt, or Link only? · cgk's list of ping lists ·
(In the meantime, I've been using Google Maps to look at lots of "Carolina Bays" in the Myrtle Beach, SC area...)
Eons ago? 13000 years isn’t even roundoff error on the “eon scale”.
If a layer of salt water sits beneath a layer of fresh water, convection will be far less effective than it would be if all water were of uniform salinity. The article's terminology is weird, however, since the salt water wouldn't be stuck on the surface but rather below.
Incidentally, ice is nearly always frozen fresh water; the act of freezing pushes out the salt. This could create variations in salinity, though in most cases natural mixing would prevent them from becoming too significant.
The big question is: where's the crater(s)?
There's plenty of craters. Earth Impact Database. (Interesting website to peruse. Just FYI, the biggest is the Vredefort ring, in South Africa. 300km across.)
Thanks for the ping. Happy New Year!
Thanks for the data...good addition to this thread.
This I understand, but the scenario is supposedly a layer of fresh water sitting beneath a layer of salt water not allowing the salt water to sink.
This isnt an issue of "terminology" but one of a complete screwup of the description of circumstances.
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