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The Last Permian Mass Extinction (LPME) was the largest mass extinction in Earth’s history.Wiped out 80-90% of life on Earth, although experts have found no conclusive evidence due to drastic climate change.
Although LPME occurred 250 million years ago, Similar to the massive climate change happening todayexplained in a statement Tracy Frank, Department of Earth Sciences University of Connecticut, and published in natural communication,
“It’s about understanding what might happen on Earth in the future. The main cause of climate change is related to the massive injection of carbon dioxide into the atmosphere at the time of the extinction, which is warming rapidly,” he said.
In the case of LPME, It is widely believed that the high temperatures associated with the event were linked to massive volcanic activity in a region called The Great Igneous Province of the Siberian Traps (STLIP), Frank said, but direct evidence is still lacking.
Volcanoes leave useful clues in the geological record. As the lava flows out, large amounts of gases, such as carbon dioxide and methane, are released into the atmosphere along with particulate matter and heavy metals.Ra and deposited on the entire planet. ,However, it’s difficult to directly link something like this to an extinction event,” Frank said. “As geologists, we look for certain features so that we can definitively pinpoint the cause.”
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In this case, the researchers focused on mercury, one of the heavy metals associated with volcanic eruptions. The trick is to find the zone where that record still exists.
Contained in the sediments of the marine environment is a continuous record of Earth’s history, which acts almost like a tape recorder, as sediments are quickly buried and preserved, Frank explained.these sediments provide rich data on extinctions and their occurrence in the ocean. Well-preserved records of this period are more difficult to find above ground.
To illustrate the point, Frank uses the example of Connecticut: a state rich in metamorphic rocks. 40-500 million years old at or near the surface, covered by glacial deposits about 23,000 years ago. “There are big gaps in the records here. You have to be lucky to keep terrestrial records, which is why they haven’t been studied as much, because there are so few of them,” Frank said.
Not all regions of the world have such large variations in the geological record, and previous LPME studies have focused on reservoirs in the northern hemisphere. However, the Sydney Basin in eastern Australia and the Karoo Basin in South Africa are two regions with excellent records for occurrence in the Southern Hemisphere and areas that the authors have studied before.
Frank, Fielding and the other co-authors were contacted by colleague and co-author Jun Shen of the State Key Laboratory of Geological Processes and Mineral Resources at the University of Earth Sciences. Obtain and analyze samples for mercury isotopes. According to Frank, Shane was able to analyze the mercury isotopes in the samples and match all the data.
“It turns out that volcanic mercury emissions, with a very specific mercury isotopic composition, were deposited at the extinction horizon. Knowing the age of these deposits, we can establish that the extinction was linked to this large event in Siberia.” Possibly related to the scale explosion. The difference in this work is that we not only analyzed mercury, but also for the first time the isotopic composition of mercury in samples from southern high latitudes in both cases.
This definitive timeline is something that scientists are trying to perfect, But as co-author Christopher Fielding points out, the more we learn, the more complicated it becomes.
“As a starting point, geologists used radioisotope dating to time the mass extinction with a high degree of accuracy at 251.9 million years. Researchers know It was at that time that the mass extinction occurred in the marine environment, and the terrestrial extinction is believed to have occurred at the same time.
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However, earlier work by Frank and Fielding found that the extinction occurred on land between 200,000 and 600,000 years ago. “It shows that the event itself wasn’t an immediate sensation. It’s not just a very bad day on Earth, so to speak, but it’s been brewing for a while, and it’s likely to be reflected in the new results.” Fit because it shows Volcanic activity is the root cause,” Fielding said.
“This is the first impact of a biohazard on land, and it happens quickly. It takes time to spread to the ocean,” he said. The event 251.9 million years ago marked a major turning point in environmental conditions in the ocean, which had been deteriorating for some time. “
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