Volcanoes May Have Caused Mass Extinctions?

Hugh Pickens writes "According to recent research, huge amounts of sulphur dioxide released by volcanic eruptions may have had more to do with wiping out dinosaurs than the meteorite strike at Chicxulub on Mexico's Yucatán Peninsula. Marine sediments drilled from the Chicxulub crater have revealed that that the mass extinctions occurred 300,000 years after Chicxulub hit Earth. The Deccan volcanism was a long cumulative process that released vast amounts of greenhouse gases into the atmosphere. '"On land it must have been 7-8 degrees warmer," says Princeton University paleontologist Gerta Keller. "The Chicxulub impact alone could not have caused the mass extinction, because this impact predates the mass extinction."' Keller also postulates a second larger and still unidentified meteor strike after Chicxulub, that left the famous extraterrestrial layer of iridium found in rocks worldwide and pushed earth's ecosystem over the brink. But where's the crater? "I wish I knew," says Keller."

Re:Pre hoc ergo propter hoc?

[Anonymous Coward]

Because a seperation of 300,000 years removes the impact as a reasonable source of the mass extinction.

Doh...

[Anonymous Coward]

How's it going to cause a mass extinction if it takes place after the mass extinction occurs?

If you had ate least read the summary, you would have realized that this "predate" here means 300000 years...

Re:Pre hoc ergo propter hoc?

[SnowNinja]

For the Chicxulub impact to have caused the mass extinction, it *must* have predated the mass extinction. How's it going to cause a mass extinction if it takes place after the mass extinction occurs?

I think what they're trying to say is that 300,000 years is a little long to actually attribute the mass extinction to the meteor. If it were the direct cause, the extinctions would have occured in a much more narrow time frame.

Re:Pre hoc ergo propter hoc?

[ByOhTek]

Given that radiocarbon dating looses too much accuracy to be useful somewhere between 5k and 10k years... I seriously doubt they used that. Especially since it wasn't mentioned in the article.

Some quick (20 second) searching found some things you might like to enlighten yourself with.
Radometric dating, methods other than just carbon [wikipedia.org]
They probably used thermoluminescence dating. [wikipedia.org]

Re:Pre hoc ergo propter hoc?

[YouTookMyStapler]

Volcanoes not only belch out gas, but aerosol droplets and ash are blasted into the stratosphere during major eruptions. If the major gas component of eruptions is carbon dioxide, that "evil" global warming gas, it will cause temps to increase globally. While on the other hand, if sulfur dioxide is the major component of an eruption it can lead to an over all global temperature drop. [pulling info from my brain from college courses]

If volcanoes, globally, are belching out a massive amount of gas, it will eventually lead to a dramatic change in atmospheric conditions. The altered atmospheric conditions will then have the domino effect on global climate. Any dramatic fluctuation in climate obviously didn't occur over a short period of time, but would have affected the dinosaurs in the long run(droughts, famine or temperatures they were not able to adapt to) and, in short, lead to the Darwinian 'survival of the fittest'. The mammals were the ones that were able to adapt, so they 'took over'.

Re:Pre hoc ergo propter hoc?

[wish bot]

Unfortunately, Keller is about the only person who believes the date of the impact is 300,000 years earlier than the extinction. A lot of people have issues with the location and interpretation of the core samples she has taken to create this theory - directly from the impact site. To me, trying to analyse samples from the impact site of an explosion 2 million times more powerful than our largest nuclear bomb blast is a pretty insane thing to do - it'd be like trying to read the tea leaves in your cup of tea after someone ran a bulldozer through your house, set fire to the rubble, dug it up and sent it to the dump.

Absolute Dating Absurdity

[pln2bz]

The idea that absolute dating techniques can survive catastrophic events without the introduction of abnormalities is rather presumptive. Just last week, there was an announcement that uranium isotopes are not invariant ...

http://http//www.sciencedaily.com/releases/2007/10/071023103947.htm [http]

What is the cause of the extraneous decay?

One Russian researcher has performed a simple experiment that demonstrates a statistical enigma within decay rates that mysteriously correlates with movements of the stars, the Sun and the Moon ...

http://www.21stcenturysciencetech.com/articles/time.html [21stcentur...cetech.com]

Charles Ginenthal has written a scathing 17-page paper on the problems associated with absolute dating titled "Scientific Dating Methods In Ruins". Of relevance ...

If it were shown that careful radiocarbon testing of an item of known age, uniformly contaminated by its surrounding environment, gave one age as a result of repeated testing or testing by several laboratories, then there would be no question regarding the concept of the technique. Let us remember that a jawbone, repeatedly tested, failed to give the same data again and again. What then of a blind test, conducted by several laboratories, of an artifact of known age? This is a crucial experiment!

In fact, the denouement came in 1989, with a blind test, conducted by the British Science and Engineering Research Council (BSERC), at 38 of the world's leading radiocarbon testing laboratories. According to Andy Coghlan, the council commissioned a blind trial that compared the accuracy with which 38 laboratories around the world dated artifacts of known age. An item of known age was divided into 38 parts. One part was sent to each testing laboratory for a full measurement of its age. After careful testing by the 38 laboratories, only seven produced results that the organizers of the trial considered to be satisfactory.(28) At the August, 1990, Symposium of the Canadian Society for Interdisciplinary Studies, Gunnar Heinsohn read from a newspaper account of the BSERC meeting, at which this evidence was disclosed. None of the testing laboratories achieved a correct date, even with plus or minus tolerances, and many were off by thousands of years.

Another interesting part ...

Frank C. Hibben also discussed the process of radiocarbon dating. After outlining several problems associated with using this method, he stated that "[e]ven with these drawbacks and pitfalls...archaeologists and laboratory technicians began to hammer out the exact history of the earliest Americans. The dates badly out of line were disregarded."(13) (Emphasis added.) With what were dates badly out of line? They were out of line with the accepted and established chronology of the history of the American continent. As Robert E. Lee informed us above, this is, apparently, quite common. Regarding this same point, Ron Willis stated that "[t]here are anomalous dates in the series [of dates] which do not fit. This is common in the C-14 process. LIKE ANY GOOD ARCHAEOLOGIST, I WILL IGNORE THE DATES THAT DO NOT FIT."(14) (Emphasis added.) Once again, we are informed that dates that do not fit the accepted chronology are ignored. We are told that finding anomalous radiocarbon dates is a common occurrence and that good archaeologists will ignore anomalous dating evidence.

Not everybody agrees that there is validity to these dates ...

"The radiocarbon method is still not capable of yielding accurate and reliable results," wrote R. E. Lee. "There are gross discrepancies, the chronology is uneven and relative, and the accepted dates are actually selected." - R. E. Lee, "Radiocarbon: Ages in Error," ANTHROPOLOGICAL JOURNAL OF CANADA, 19 (1981), p. 27

I caused the mass extinction

[tjstork]

I do not care much for lizards. They are big, stupid and slow, and they smell. All these dinosaurs are around, and I hated them all, but there's all sorts of stupid regulations about dinosaurs, thanks to Al Gore leading the save the dinosaur charge.

So I hopped into my time machine, gathered up some of the world's famous hunters, went back in time and killed the dinosaurs. Me and Buffalo Bill must have slaughtered 1,200 T-Rex's in what is now Montana, just in one night of drinking and hooting and hollering and a-shooting.

Those of you wonder what really happened to Jesse James, though, should know that he really did die 65 million years ago. We were playing cards one night after a big hunt and I drew a royal flush to his full house. Jesse probably wouldn't blown my head off in anger, but Buffalo Bill was quicker on the draw and he said, "Don't even do it Jesse." Jesse stuffed his revolver back into his holster, grabbed the bottle and went off in a huff. But as he was a stompin' away, he was set on by a pack of raptors and chewed up. It was a sad thing, but T.R. was able to go shoot two down with that pistol of his, and, thus, while we couldn't save Jesse, we at least saved the bottle of whiskey.

I reckon it took us a few months to kill all them dinosaurs. Since they all ate the biggest dinosaurs, we just took out all the brontos and crushed their eggs, and the rest all starved. We shot a bunch too. And then I dropped everyone back into their own times, and came back to this one, and there was not a dinosaur to be found.

Thank god!

So I called upon Mr. Gore to see if he remembered how much he liked dinosaurs in this adjusted timeline, and he said that he thought dinosaurs were ok in their own time, and said that, if we didn't do something about global warming, dinosaurs might come back.

So now, I gotta back in time and gather up the boys and go visit henry ford.

Ah, the work that we do!

Re:Cause

[Miraba]

That's already been proposed. See the entry on the Shiva crater [wikipedia.org].

Re:Absolute Dating Absurdity

[zerocool^]

For starters, the 21st Century Science and Technology [wikipedia.org] is NOT a reputable, peer-reviewed scientific journal. It is a group of quacks. Literally, the magazine (which is not even printed anymore, copies are available now as pdf only) is a thinktank of scientists who challenge "the assumptions of modern scientific dogma, including quantum mechanics, relativity theory, biological reductionism, and the formalization and separation of mathematics from physics." (from their statement of purpose).

Furthermore, the "21st century" publication follows the line of groupthink known as the LaRouche Movement [wikipedia.org], a wacky pseudo-political group of conspiracy theorists and nutcases. Their group spews fascist, anti-semetic ideology like it's going out of style.

That alone makes your bullshit transparent, but you state that you want something other than attacks on credentials (I happen to believe that scientists stand or fall on their credentials, including past bodies of work, but whatever). So, in a nutshell, Radiometric Dating [wikipedia.org], including Carbon-14 dating and other methods such as Rubidium-strontium dating and Uranium-lead dating, is EXTREMELY accurate and accepted by all reputable scientists and peer-reviewed scientific journals.

So, if your russian scientist is the only one shouting that it's inaccurate, we must be left asking "Why does every other scientist accept it, and what is his axe to grind?".

~Wx

Re:Pre hoc ergo propter hoc?

[IdleTime]

Aye! This is true.

Esp. in this area since the two parties are so at the throat of each other that it is difficult to take anything they say for good fish. Gerta Keller is quite hateful and very angry because her funding was taken away after some umm unconventional outbursts from her side.

Keller's far-out

[yusing]

The 300,000 year hypothesis isn't widely supported.

"Many scientists reject Keller's analysis, some arguing that the 10 meter (32.8 ft) layer on top of the impact spherules should be attributed to tsunami activity resulting from impact. Few researchers support Keller's dating of the impact crater." -- Wikipedia ... http://en.wikipedia.org/wiki/K [wikipedia.org]-T_boundary