Double whammy causes mass extinctions

Discovery News ^ | Tuesday, October 24, 2006 | Larry O'Hanlon

[SunkenCiv]

"[The theory] is essentially a more eloquent way of saying what I and many other palaeontologists have been saying for many years," says Professor Gerta Keller of Princeton University. "Namely that the impact-kill hypothesis is all wrong. Impacts alone could not have been the killing mechanism for the K-T [Cretaceous-Tertiary event] or any of the other major mass extinctions." ... "I'm very happy they have done the analysis based on the literature and come up with the same conclusions that palaeontologists have been preaching all along," Keller says.

[SunkenCiv]

The claims in this article are garbage. This is just another in a long line of attempts to discount the impact of rare catastrophic events. The Chicxulub impact has been shown as the impact event that ended the Cretaceous, and denial of that fact is merely stupid. Before the impact crater was identified, the whining from the gradualist ninnies was that no impact crater had been identified.

The summary of the gradualist argument is -- The impact happens, and the fossils in the subsequent strata don't include the major land critters found in the preceding strata. But there was already pressure on those taxa, and the impact / eruption / whatever was just enough to put them over the edge so they all died off. IOW, it was just a HUGE COINCIDENCE.

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No single event, like a huge meteor strike, is solely responsible for a mass extinction, says new research. Not even the demise of the dinosaurs 65 million years ago (Image: (Image: Don Davis/NASA)

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[SunkenCiv]

Dino asteroid led to 'global devastation'
by Helen Briggs
BBC News Online
November 22, 2001

Fossils uncovered in New Zealand point to major disturbances in climate that led to the death of most trees and flowering plants. Clues from the plant fossil record suggest that even the Southern Hemisphere experienced an artificial winter, acid rain, and raging forest fires. This is the first clear fossil evidence for destruction of plant life so far from the Mexico coast, where the space object is believed to have landed. Dr Timothy Flannery, an expert at the South Australian Museum in Adelaide, told BBC News Online: "The asteroid devastated pretty much everything. "This was a case of global devastation rather than North American catastrophe."

[SunkenCiv]

Study: Dinosaurs Died Within Hours After Asteroid Hit Earth 65 Million Years Ago
CU-Boulder
May 24, 2004

According to new research led by a University of Colorado at Boulder geophysicist, a giant asteroid that hit the coast of Mexico 65 million years ago probably incinerated all the large dinosaurs that were alive at the time in only a few hours, and only those organisms already sheltered in burrows or in water were left alive... The "heat pulse" caused by re-entering ejected matter would have reached around the globe, igniting fires and burning up all terrestrial organisms not sheltered in burrows or in water, he said... "The kinetic energy of the ejected matter would have dissipated as heat in the upper atmosphere during re-entry, enough heat to make the normally blue sky turn red-hot for hours," said Robertson. Scientists have speculated for more than a decade that the entire surface of the Earth below would have been baked by the equivalent of a global oven set on broil.

[SunkenCiv]

[SunkenCiv]

'Quick' demise for the dinosaurs
by BBC News Online's Jonathan Amos
Thursday, March 8, 2001

Sujoy Mukhopadhyay and colleagues studied sedimentary rocks that mark the so-called K-T boundary, the line of separation between the zones of geological time referred to as the Cretaceous period and the Tertiary sub-era. It is at this K-T boundary, timed at about 65 million years ago, that 70% of all life, including the dinosaurs, suddenly disappears from the fossil record... Mukhopadhyay's US-Italian team believe they can now measure the length of this dark period in Earth history. They analysed the amount of helium-3 in the rocks of the K-T boundary. Levels of this type, or isotope, of the element reflect the amount of interplanetary dust that settles on Earth and, properly calibrated, can be used as a tool to time the rate at which rocks are laid down... The research suggests the K-T boundary was deposited in about 10,000 years. He said the short period lent support to the theory that the dinosaurs were wiped out in a sudden, catastrophic event such as the impact of an extraterrestrial body. The constant rate of accumulation of helium-3 also indicates that the impactor was not part of a comet shower or bombardment. "Comets are dusty objects and if you have several comets coming into the inner Solar System, you will increase the dust flux to the Earth," Mukhopadhyay said. "If you increase the dust flux, you increase the helium-3 flux. And so if you don't see an increase in the helium-3 in these sediments, it rules out a large number of comets coming in."

[r9etb]

The impact happens, and the fossils in the subsequent strata don't include the major land critters found in the preceding strata. But there was already pressure on those taxa, and the impact / eruption / whatever was just enough to put them over the edge so they all died off.

I keep waiting for the impact that will extinctify the Democrat Party....

[SunkenCiv]

I have hope and some optimism that it will happen early in November. :')

[jonno]

Mass extinction - on a global scale?

Hmmm - I wonder if a world-wide flood would do it?

8^)

[Coyoteman]

Mass extinction - on a global scale?

Hmmm - I wonder if a world-wide flood would do it?

8^)

The dating is off by about 65 million years.

[nativesoutherner]

They might want to consider the location of the Deccan Traps on the Indean sub-continent versus the K-T impact crater's location in relation to hydrostatic shockwaves through the mantle as the cause of the Trapps.

[cogitator]

Just a word of advice; never cling too strongly to a given explanation as the sole and certain explanation for something (speaking about scientific topics here). The universe is just too complex. Most observed effects have multiple causes, even if there is a single, clearly dominant cause for many effects.

[SunkenCiv]

Thanks, but such advice should be directed toward those (like the purported researchers quoted in the article) who cling to a single explanation while (and by) rejecting one that they can't accept, and don't bother to understand.