Posted on 10/31/2007 3:08:40 PM PDT by blam
Volcanic Eruptions, Not Meteor, May Have Killed The Dinosaurs
Rajahmundry Quarry. Keller's crucial link between the eruption and the mass extinction comes in the form of microscopic marine fossils that are known to have evolved immediately after the mysterious mass extinction event. The same telltale fossilized planktonic foraminifera were found at Rajahmundry near the Bay of Bengal, about 1000 kilometers from the center of the Deccan Traps near Mumbai. (Credit: Photo courtesy Gerta Keller)
ScienceDaily (Oct. 30, 2007) — A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico. The eruptions, which created the gigantic Deccan Traps lava beds of India, are now the prime suspect in the most famous and persistent paleontological murder mystery, say scientists who have conducted a slew of new investigations honing down eruption timing.
"It's the first time we can directly link the main phase of the Deccan Traps to the mass extinction," said Princeton University paleontologist Gerta Keller. The main phase of the Deccan eruptions spewed 80 percent of the lava which spread out for hundreds of miles. It is calculated to have released ten times more climate altering gases into the atmosphere than the nearly concurrent Chicxulub meteor impact, according to volcanologist Vincent Courtillot from the Physique du Globe de Paris.
Keller's crucial link between the eruption and the mass extinction comes in the form of microscopic marine fossils that are known to have evolved immediately after the mysterious mass extinction event. The same telltale fossilized planktonic foraminifera were found at Rajahmundry near the Bay of Bengal, about 1000 kilometers from the center of the Deccan Traps near Mumbai. At Rajahmundry there are two lava "traps" containing four layers of lava each. Between the traps are about nine meters of marine sediments. Those sediments just above the lower trap, which was the mammoth main phase, contain the incriminating microfossils.
Previous work had first narrowed the Deccan eruption timing to within 800,000 years of the extinction event using paleomagnetic signatures of Earth's changing magnetic field frozen in minerals that crystallized from the cooling lava. Then radiometric dating of argon and potassium isotopes in minerals narrowed the age to within 300,000 years of the 65-million-year-old Cretaceous-Tertiary (a.k.a. Cretaceous-Paleogene) boundary, sometimes called the K-T boundary.
The microfossils are far more specific, however, because they demonstrate directly that the biggest phase of the eruption ended right when the aftermath of the mass extinction event began. That sort of clear-cut timing has been a lot tougher to pin down with Chicxulub-related sediments, which predate the mass extinction.
"Our results are consistent and mutually supportive with a number of new studies, including Chenet, Courtillot and others (in press) and Jay and Widdowson (in press), that reveal a very short time for the main Deccan eruptions at or near the K-T boundary and the massive carbon dioxide and sulfur dioxide output of each major eruption that dwarfs the output of Chicxulub," explained Keller. "Our K-T age control combined with these results strongly points to Deccan volcanism as the likely leading contender in the K-T mass extinction." Keller's study was funded by the National Science Foundation.
The Deccan Traps also provide an answer to a question on which Chicxulub was silent: Why did it take about 300,000 years for marine species to recover from the extinction event? The solution is in the upper, later Deccan Traps eruptions.
"It's been an enigma," Keller said. "The very last one was Early Danian, 280,000 years after the mass extinction, which coincides with the delayed recovery."
Keller and her colleagues are planning to explore the onset of the main phase of Deccan volcanism, that is, the rocks directly beneath the main phase lavas at Rajahmundry. That will require drilling into the Rajahmundry Traps, a project now slated for December-January 2007/2008.
Keller and her collaborator Thierry Adatte from the University of Neuchatel, Switzerland, are scheduled to present the new findings on Tuesday, 30 October, at the annual meeting of the Geological Society of America in Denver. They will also display a poster on the matter at the meeting on Wednesday, 31 October.
Adapted from materials provided by Geological Society of America.
Catastrophism Ping.
I would imagine that when the meteor hit, it would have triggered massive volcanism all over the planet from the force of the impact on the crust................
Interesting.
There’s actually another meteor crater (Shiva?) near India from about the same time, more likely to have uncorked the volcanos.
Could have been part of a “swarm” of meteors that impacted roughly at the same time.......
BUSH’S FAULT!!!!!
bump
And weren’t the flood basalt lava flows going great guns in Siberia around the same time? Looks like the egg was hit really hard and sprung a few leaks.
No, I think this one WAS global warming..................
How about this... giant meteor stuck the earth, caused catastrophic volcanism. Geez. lol If something the size of the asteroid that hit the Yucatan were to hit today, you can bet your bobby socks that there would be massive volcanism set off in the Pacific Rim, and plenty of places there haven’t been active volcanoes in many centuries.
The debate is OVER! Meteors struck and Dinosaurs DIED!
IMPEACH!
oh, sorry, I got carried away there.
But your reasonable explanation would not get the headline attention ...
Some days it just stinks to be The Earth.
Yeah, well, but but but. LOL
I get pretty tired of people “rethinking” things which are based on pretty certain science now> For instance, there are several large events that occurred at the same time, or very near the same time as the K-T event. The problem is, the evidence STRONGLY points to layers of iridium allowing dating pretty precisely (within a couple tens of thousands of years anyway) and to just blithely go off saying “Oh it was the VOLCANOES” without taking into account the other facts, isn’t science, it’s now speculation.
There’s also the fact that some things have a cause and effect relationship, including if a very large asteroid plows into the Earth, the whole planet is going to feel it, and other effects are going to happen. Including massive volcanism.
But, what do I know. I’ve only been doing the stuff I do for 40 years. HAHA!
It’s not the slip that causes the damage - it’s the fall...
SUV’s caused it all and they went extinct too at the same time....only to return now to seek out more revenge on humans.
The death of the dinosaurs may have had more than just one cause.
“Volcanic Eruptions And Global Warming Likely Cause Of Great Dying 250 Million Years Ago”
“Powers and others believe that the same deadly sequence repeated itself for another major extinction 200 million years ago, at the end of the Triassic era.”
“There are very few people that hang on to the idea that it was a meteorite impact,” she said.
http://www.sciencedaily.com/releases/2007/10/071025091047.htm
Very few people believe a meteor impact killed off the dinosaurs? I thought that was still the prevailing theory.
“Earth’s volcanism linked to meteorite impacts”
“Large meteorite impacts may not just throw up huge dust clouds but also punch right through the Earth’s crust, triggering gigantic volcanic eruptions.”
“The idea is controversial, but evidence is mounting that the Earth’s geology has largely been driven by such events.”
http://www.newscientist.com/article/dn3171.html
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