Permian mass exctinction (Introduction)
by David Turell 
, Wednesday, February 12, 2014, 19:37 (3937 days ago)
Set evolution for the next step. Took only 60,ooo years:-http://www.scientificamerican.com/article/worst-mass-extinction-ever-took-only-60000-years/?&WT.mc_id=SA_DD_20140212
Permian mass exctinction
by David Turell , Wednesday, February 01, 2023, 14:47 (661 days ago) @ David Turell
New evidence:
https://www.sciencealert.com/embers-of-an-ancient-inferno-pinpoint-the-worst-extinction...
"The link between ancient volcanic eruptions and the most severe extinction event the world has ever seen just got even stronger. A new analysis of mercury isotopes has provided evidence that a quarter of a billion years ago, far-flung places in Earth's Southern Hemisphere were blanketed with debris from volcanic eruptions in Siberia.
"The so-called Great Dying, also called the Permian-Triassic mass extinction event, ensued, where most of life was wiped out under ash-filled skies.
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"Through piecing together chemical traces trapped in rocks and ocean sediments, geoscientists are fairly confident that a series of volcanic eruptions unleashed a cascade of dramatic changes in Earth's atmosphere and oceans that eventually suffocated animals.
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"paleoclimatologist Jun Shen of China University of Geosciences and colleagues set about detecting mercury isotopes in rock deposits in two Southern Hemisphere locations: the Karoo Basin in south-central Africa and Sydney Basin on Australia's east coast.
"At the time of the Great Dying, the basins were united in one supercontinent called Pangaea, but are now separated by roughly 10,000 kilometers (6,200 miles) and the Indian ocean. In them, the researchers found near-identical patterns: mercury isotopes peaked around the end of the Permian.
"This evidence – from what are to date the most distant terrestrial sites from the Siberian Traps, the gigantic lava flows formed by the epoch-ending volcanoes in question – suggests mercury was blasted out of volcanoes in the Northern Hemisphere and swept around the globe, the researchers say.
"'It turns out that volcanic emissions of mercury have a very specific isotopic composition of the mercury that accumulated at the extinction horizon," explains study author and University of Connecticut geologist Tracy Frank.
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"Their work aligns with signals from sulfur isotopes coinciding with the Great Dying, and also builds on past research which suggests mass extinctions started occurring on land up to 600,000 years before marine life sucked in its last few breaths.
"'That suggests that the event itself wasn't just one big whammy that happened instantaneously," explains Christopher Fielding, another geologist at the University of Connecticut.
"'It wasn't just one very bad day on Earth, so to speak, it took some time to build and this feeds in well into the new results because it suggests the volcanism was the root cause."
"The researchers acknowledge that nailing down the direct cause of the Great Dying is not easily done. Plumes of ash from volcanic eruptions in southern China have also been implicated in the carnage, in addition to the Siberian Traps."
Comment: I'm going to stick with my theory that these events were natural, not under God's control, and He was powerful enough to work around them. Remember He knew they were coming.
Permian mass extinction; not so wide-spread
by David Turell , Friday, February 10, 2023, 18:29 (652 days ago) @ David Turell
New Chinese finding:
https://www.sciencenews.org/article/historys-deadliest-mass-extinction-ocean-life
"Following the most severe known mass extinction in Earth’s history, vibrant marine ecosystems may have recovered within just a million years, researchers report in the Feb. 10 Science. That’s millions of years faster than previously thought. The evidence, which lies in a diverse trove of pristine fossils discovered near the city of Guiyang in South China, may represent the early foundations of today’s ocean-dwelling ecosystems.
"The conventional story was that the ocean was kind of dead for millions of years after this mass extinction, says paleontologist Peter Roopnarine of the California Academy of Sciences in San Francisco, who was not involved in the research. “Well, that’s not true. The ocean [was] very much alive.”
"The Great Dying, or Permian-Triassic mass extinction, occurred around 251.9 million years ago, at the end of the Permian Period, after a series of massive volcanic eruptions (SN: 12/6/18).
“T'he oceans warmed significantly, and there’s evidence for acidification, deoxygenation [causing widespread dead zones], as well as poisoning,” says Roopnarine. “There [were] a lot of toxic elements like sulfur entering into parts of the ocean.”
"Life in the seas suffered. More than 80 percent of marine species went extinct. Some researchers have even proposed that entire trophic levels — castes in an ecosystem’s food web — may have vanished.
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"From 2015 to 2019, Dai, now at the University of Burgundy in Dijon, France, and his colleagues uncovered a bricolage of fossilized life: Predatory fish as long as baseball bats. Ammonoids in swirled shells. Eel-like conodonts. Early shrimps. Sponges. Bivalves. Fossilized poo.
"And the prizes kept coming. Both under and within the Guiyang biota, Dai and his colleagues discovered beds of volcanic ash. An analysis of the amounts of uranium and lead in the ash revealed that the Guiyang biota contained fossils from roughly 250.7 to 250.8 million years ago (SN: 5/2/22). The dating was further supported by the types of fossils found and by an analysis of the different forms of carbon in the rocks.
Finding a potpourri of life of this age suggests that marine ecosystems rebounded quickly after the Great Dying, within just 1 million years or so, Dai says.
"Alternatively, it may indicate that the extinction event failed to wipe out entire trophic levels, says paleontologist William Foster from the University of Hamburg in Germany, who was not involved in the study. “You have this really environmentally stressful world, but some former marine ecosystems survive.”
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"According to Dai, the fossils may be evidence that the roots of today’s marine ecosystems took hold shortly after the Great Dying. “These groups are related to modern fish, lobsters and shrimps, their ancestors,” he says. “The oldest time we can find similar seafood to today is [in the time of] the Guiyang biota.'”
Comment: this fits my approach that God was not fully in charge of all factors. He took advntage of these changes to advance evolution..