World's Biggest Extinction Event: Massive Volcanic Eruption, Burning Coal and Acceler

[ScienceRocks]

World's Biggest Extinction Event: Massive Volcanic Eruption, Burning Coal and Accelerated Greenhouse Gas Choked out Life

ScienceDaily (Jan. 23, 2011) — About 250 million years about 95 per cent of life was wiped out in the sea and 70 per cent on land. Researchers at the University of Calgary believe they have discovered evidence to support massive volcanic eruptions burnt significant volumes of coal, producing ash clouds that had broad impact on global oceans.


"This could literally be the smoking gun that explains the latest Permian extinction," says Dr. Steve Grasby, adjunct professor in the University of Calgary's Department of Geoscience and research scientist at Natural Resources Canada.

Grasby and colleagues discovered layers of coal ash in rocks from the extinction boundary in Canada's High Arctic that give the first direct proof to support this and have published their findings in Nature Geoscience.

Unlike end of dinosaurs, 65 million years ago, where there is widespread belief that the impact of a meteorite was at least the partial cause, it is unclear what caused the late Permian extinction. Previous researchers have suggested massive volcanic eruptions through coal beds in Siberia would generate significant greenhouse gases causing run away global warming.

"Our research is the first to show direct evidence that massive volcanic eruptions -- the largest the world has ever witnessed -caused massive coal combustion thus supporting models for significant generation of greenhouse gases at this time," says Grasby.

At the time of the extinction, the Earth contained one big land mass, a supercontinent known as Pangaea. The environment ranged from desert to lush forest. Four-limbed vertebrates were becoming more diverse and among them were primitive amphibians, early reptiles and synapsids: the group that would, one day, include mammals.

The location of volcanoes, known as the Siberian Traps, are now found in northern Russia, centred around the Siberian city Tura and also encompass Yakutsk, Noril'sk and Irkutsk. They cover an area just under two-million-square kilometers, a size greater than that of Europe. The ash plumes from the volcanoes traveled to regions now in Canada's arctic where coal-ash layers where found.

Grasby studied the formations with Dr. Benoit Beauchamp, a professor in the Department of Geoscience at the University of Calgary. They called upon Dr. Hamed Sanei adjunct professor at the University of Calgary and a researcher at NRCan to look at some of peculiar organic layers they had discovered.

"We saw layers with abundant organic matter and Hamed immediately determined that they were layers of coal-ash, exactly like that produced by modern coal burning power plants," says Beauchamp.

Sanei adds: "Our discovery provides the first direct confirmation for coal ash during this extinction as it may not have been recognized before."

The ash, the authors suggest, may have caused even more trouble for a planet that was already heating up with its oceans starting to suffocate because of decreasing oxygen levels.

"It was a really bad time on Earth. In addition to these volcanoes causing fires through coal, the ash it spewed was highly toxic and was released in the land and water, potentially contributing to the worst extinction event in earth history," says Grasby.
Email or share this story:
| More


World's biggest extinction event: Massive volcanic eruption, burning coal and accelerated greenhouse gas choked out life
...

I thought this was caused by another goddamn Asteroid. learn something new every day.

 

[Old Rocks]

Mathew, that information postdates the information at this site, however, it suplements it rather than replacing it.

Methane catastrophe

This was written as the author was doing graduate studies. It is quite informative as to the proxy methods used. Well worth the read.

 

[Old Rocks]

There are also coal formations in Australia and China that show much the same effects. The one is China is earlier by about 4 million years than the Siberian Traps, but in line with an extinction event at that time. The one in Australia was contemperanous with the Siberian Traps.

 

[waltky]

Mega-Eruptions Caused Mass Extinction ...

Mega-eruptions Caused Mass Extinction, Study Finds
March 21, 2013 - Behind the extinction that wiped out at least half of Earth’s species.

At the end of the Triassic period, at least half of the species living on land and in the ocean went extinct, opening the way for dinosaurs to dominate Earth for the next 135 million years. Scientists have long suspected massive volcanic eruptions were to blame, but they haven’t been able to pin down the exact timing until now. In a new study published today in the journal Science, researchers say they have confirmed that eruptions large enough to bury the U.S. under 300 feet (91 meters) of lava occurred at the same time that vast numbers of plant and animal species disappeared from the fossil record.

Along sea cliffs in southern England, geologist Paul Olsen of Columbia University's Lamont-Doherty Earth Observatory samples rocks from near the 201,564,000-year Triassic extinction boundary.

About 201 million years ago, tectonic forces started ripping the supercontinent known as Pangaea apart, said Terrence Blackburn, a geologist at the Carnegie Institution for Science in Washington, D.C., and lead author of the study. The underlying mantle rock melted, generating these large eruptions, he added. The rift, which eventually created the Atlantic Ocean basin, happened between sections of Pangaea that would go on to become North America and Africa. (Read about how Pangaea formed.)

These huge eruptions, or flood basalt events, occurred during four periods over 600,000 years, but it’s the first bout of volcanism that contributed to the death of so many organisms, said Blackburn. Some ancient crocodilian ancestors, eel-like animals called conodonts, and a mammalian group called therapsids were all hammered, with many disappearing from the fossil record around this time.

Time Capsule

See also:

Dinosaur-killing space rock 'was a comet'
22 March 2013 - The space rock that hit Earth 65m years ago and is widely implicated in the end of the dinosaurs was probably a speeding comet, US scientists say.

Researchers in New Hampshire suggest the 180km-wide Chicxulub crater in Mexico was carved out by a smaller object than previously thought. Many scientists consider a large and relatively slow moving asteroid to have been the likely culprit. Details were outlined at the 44th Lunar and Planetary Science Conference. But other researchers were more cautious about the results. "The overall aim of our project is to better characterise the impactor that produced the crater in the Yucatan peninsula [in Mexico]," Jason Moore, from Dartmouth College in New Hampshire, told BBC News. The space rock gave rise to a global layer of sediments enriched in the chemical element iridium, in concentrations much higher than naturally occurs; it must have come from outer space.

The impact 65 million years ago killed off 70% of species on Earth - including the dinosaurs

Extra-terrestrial chemistry

However, in the first part of their work, the team suggests that frequently quoted iridium values are incorrect. Using a comparison with another extraterrestrial element deposited in the impact - osmium - they were able to deduce that the collision deposited less debris than has previously been supposed. The recalculated iridium value suggests a smaller body hit the Earth. So for the second part of their work, the researchers took the new figure and attempted to reconcile it with the known physical properties of the Chicxulub impact. For this smaller space rock to have produced a 180km-wide crater, it must have been travelling relatively quickly. The team found that a long-period comet fitted the bill much better than other possible candidates. "You'd need an asteroid of about 5km diameter to contribute that much iridium and osmium. But an asteroid that size would not make a 200km-diameter crater," said Dr Moore. "So we said: how do we get something that has enough energy to generate that size of crater, but has much less rocky material? That brings us to comets."

Dr Moore's colleague Prof Mukul Sharma, also from Dartmouth College, told BBC News: "You would need some special pleading for an asteroid moving very rapidly - although it is possible. But of the comets and asteroids we have looked at in the skies, the comets are the ones that are moving very rapidly." Long-period comets are balls of dust, rock and ice that are on highly eccentric trajectories around the Sun. They may take hundreds, thousands or in some cases even millions of years to complete one orbit. The extinction event 65 million years ago is now widely associated with the space impact at Chicxulub. It killed off about 70% of all species on Earth in just a short period of time, most notably the non-avian dinosaurs. The enormous collision would have triggered fires, earthquakes and huge tsunamis. The dust and gas thrown up into the atmosphere would have depressed global temperatures for several years.

Lost in space