Glaciers ‘bulldozed’ snowball Earth and changed ocean chemistry, paving the way for complex life, scientists say

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For more than half a billion years ago, on the ground covered by ice, the ice rivers have sparked components of complex life through the landfly cavity and then depositing them in the ocean, according to a new study.

Inch, while the huge ice rivers infiltrated the frozen lands towards the sea covered with the ice, they wandered below, wandering around the rocks of the Earth’s crust. When the ice rivers ultimately melted, they released a flood of Earth’s chemicals in the ocean, according to the researchers recently. The minerals were swept up on the ground through the “ice vacuum” that changed the marine chemistry and the oceans that were instilled with the nutrients that they say may have formed the complex development of life.

This old period of deep freezing, known as Neoproterozoic eraOr “Snowball Earth”, lasted from about one billion to 543 million years. During that time, the ground block was unified in the continent called Rodinia and then separated again. The oldest forms of life for the Earth, such as microbes, blue bacteria, sponge and living organisms on the sea floor, canceled the oceans. After the end of Neoproterozoic, a more complex life appeared, with the first appearance appeared Marine creatures are sports shieldShells and nails.

Scientists have attributed this evolutionary mutation to Increase oxygen levels In the atmosphere of the Earth and in shallow ocean waters. Now, research was published on Tuesday in the magazine Geology It indicates that the flow of old icebergs may have chemical changes directly in the ocean that were decisive to the development of complex organisms.

Dr. Chris Kurchland, the author of the study’s main study, said that the Snowball Earth study provides a window in the past of our planet, but also provides valuable visions in modern climate change.

He said: “Our deep geological record indicates how to change part of the Earth on another.” At the present time, the dramatic warming of the planet, which represents the human climate crisis, occurs very quickly compared to these ancient operations that lasted millions of years.

“This rapid pace limits the Earth’s ability to organize itself naturally, which confirms the urgency to address the change of human climate creature.”

From Snowball Earth to Planet Hothouse

It is known that the movement of the iceberg, or flogging, gets rid of the ground deposits and moves them to the oceans, lakes and rivers, and forms the basis of water food networks. However, researchers who study the old earth were in the past if Neoproterozoic was absolutely moved, not to mention the erosion of the earth under it and the transportation of minerals to the sea.

“It has been assumed that the ice erosion on a wide range of continental interiors can be caused by snow snow,” said Kurchland, a professor at the Faculty of Earth Sciences and Planets at the University of Kurtin at Barth, Australia. “However, the aspects of this idea were not clear because the ice may not move or move a little or even already flow.”

Kurchland and his colleagues found answers in Scotland and Northern Ireland, where they studied sediments from rock formations dating back to Neoproterozoic. The team looked at Zircon – the crystallized minerals that are exceptionally solid and can overcome extremist geological events. Zircon also contains uranium. By measuring the stages of uranium caries in zircon, geologists use minerals as a Cronomer to study the past.

The researchers studied the sediments dating back to the time when the Earth was covered with ice, and from the period “HotHouse Earth” after millions of years when the ice disappeared, and found that the metal composition of the snowball deposits is greatly different from those in the subsequent sediments.

“We have regained distinctive patterns in groups of these metal pills,” Kirkend told CNN in an email. “In essence, the” DNA “fingerprint changed to these sedimentary rocks.

Dr. Graham Shields, a professor of geology at the University of London, said the results enhance the idea of ​​active flogging “somewhat.” Shields did not participate in the new research. However, the study did not include data from an important ice break called MarinoWhich was the end of the snowball, told CNN in an email. Shelds was also cautious about linking ice corrosion directly to the development of complex life.

“This call has been suggested before, but it is controversial because the link is assumed instead of explaining it,” Shields said. “Changing the dramatic landscape that causes the appearance of samples is an elegant idea, but the paper offers a hypothesis about the ice/wavy corrosion that can be tested, rather than settling the discussion.”

Meluing comprehensive ice turns oceans

The rocks from the time of Snowball Earth contained ancient minerals, but also participated in a group of metal eras, hinting that the rocks were exposed and eroded over time through the scraping movement of ice escapes. This guide told scientists that the ice rivers in Neoproterozoic were mobile. The younger rocks, when the earth was dissolved with snow, was a narrower set of mineral ages, and the most fragile grains were absent, indicating that the flowing water had been dissolved in the past.

When Neoproterozoic retreated, one of the known changes in ocean chemistry was an increase in uranium. Other research has already shown this increase because it is the result of high oxygen in the atmosphere, “however, our data indicates that the delivery of chemical elements in the oceans also played a role in this,” said Kurchland.

He added: “The missing component” missing “in these rocks is seen” reserve “in changes in the ocean chemistry at this time. By drawing the maps of these changes in the terrestrial and sea environments, “We are photographing the transfer of chemical elements across the earth as a system.”

Scientists have reported that the major flogging events took place at least twice between 720 million and 635 million years. By the end of the neoproterozoic, when the ice covering of the earth began in the melting of the ice, the main bouts of the chemistry occurred in the atmosphere of the earth and the oceans.

“The end of this ice is characterized by rapid increases in oxygen in the atmosphere and the ocean, and perhaps because of the strengthening of the wavy of exposed rock surfaces and increased nutrient flows in the ocean,” Kurchland said. Such changes can have instilled nutrient courses and provide emerging life with the support you need to develop into more complex forms.

“The idea that the ice debris is from the icebergs and provided nutrients to support early animal development for a while,” said Dr. Andrew Kanoul, an honorary professor of Earth sciences and planets at Harvard University, who did not participate in the new research. However, there are still questions about whether the minerals poured into the ocean by NeoProterozoic were sufficient to stimulate the long -term environmental changes with biological consequences.

Other research has previously suggested that the effects of flogging events, such as those described in the new study, “may have only transient consequences – a bit of nutrients that raise initial production and perhaps increase oxygen levels, before relaxing to the previous state of the environment,” said KNOLL. The new results added, “An interesting addition to the conversation.” “But the conversation continues.”

Lessons for the climate crisis today

From neoproterozoic to the present time, similar climate changes, including the role that carbon dioxide plays (CO2) and behavior Ring reactionsWhen a process is fed on the side of the climate system on the ground and intensifying it. Ancient climatic evidence lights up what happens during climatic transformation points-when the threshold is crossed, which leads to large-scale changes often irreversible.

today, Heat Quickly instead of cooling gradually over time. Kurchland said that it took millions of years to overcome the planet during the snowball stage on Earth, while modern warming is accelerating for decades only, “much faster than the last natural climate attacks,” said Kurchland.

He added that the global progress of climate change is still appointed by studying the interaction between the accumulation of carbon dioxide, comments rings and transformation points.

He said: “We can see how different parts of the planet are associated with chemical bonds.” “Change one part of the system, and other parts also change.”

Mindy Wespress is a scientific writer and media producer who has appeared in the field of living science, American scientific and how he works as a magazine.

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