The stone outcrop in the remote corner of the northern Quebec looks calm in its terrible insulation on the eastern bank of the Hudson Bay of Canada.
However, in the last two decades, this has been revealed by the ancient ocean floor remains known as the “Nuvuagittu Greenstone Belt”, was a hot scientific place to determine the oldest rocks in the Earth.
New studies show that the geological site has the oldest known surviving fragments of the Earth’s crust dating back to 4.16 billion years ago. It is the only rock determined to be from the first four geological centuries in the history of our planet: Hadean, which began 4.6 billion years ago, when the world was hot, restless and hell.
“Rokai is a book geologist … And we are currently lacking in a book (on Hadean).” Nuvuagittuq Greenstone Belt would be at least one page of that book, so it is so important, “said geologist Jonathan O’Neil, author of a study published on Thursday in Science.
The belt of the Navuagittuq Greenstone is dated several times by different research groups with very different results. Most agree that the rocks are at least 3.75 billion years, but this would not do its oldest land.
Closely from the Navuagittu Greenstone Belt, Nunavik, Quebec, Quebec, Quebec, Quebec, Quebec, Quebec. – Jonathan O’Neil
The Acasta Gneiss complex, a group of rock, along the bank of the river, nearly 200 miles (300 kilometers) north of Yellowknife, northwestern Canada, is more of the oldest geological formation of the planet. These rocks are unequivocally dated 4.03 billion years, marking the boundary between Hadean Eon and other Land History Department: Archean. (The planet has older rocks, but not from the planet that is not part of this discussion: some meteorites are 4.5 billion years old.)
Controversial in 2008 Paper consisting of o ‘Neil, who studied the site since it was a PhD student, said that the Nuvuagittu Greenstone Belt had been 4.3 billion years; However, other geologists were considering the boundaries of dating methods and how data was interpreted. With this latest document O’Neil, he is now an associate professor at the Department of Land and Environment of the University of Ottawa, seeking to prove that his critics are wrong.
How to see with rock
Dating rocks include radiometric methods that use the natural and spontaneous radioactive decay of certain rock elements, which acts as a type of clock.
O’Neil uses an hourglass analogy: Imagine at the top (radioactive elements) and at the bottom you count sand grain (radioactive elements) and bottom (elements made of radioactive degradation). Knowing the speed of flowing grains (which shows the speed of decomposition), scientists can be apparent with stones. Some of these radiometric watches are strong and can withstand high temperature and pressure that the Earth’s crust has endured forever, while others are more affected by these processes.
The golden standard and the easiest way to see very old rock formation is with a very solid mineral known as a zirconia. These small crystals include a bit of uranium in their structure, and researchers can accurately determine their age by measuring the degradation of the radioactive uranium atoms, which turns into a lead at a known speed.
However, at the Nuvuagittu Greenstone belt, which was linked after a survey of geology in the 1960s, but in the early 2000s, scientific attention is first and few rocks with zirconia, as they are rarely in specimens with lower silicon levels, including those who were once ancient ocean feathers.
“We tried to find zircons. They simply aren’t, or they are formed later during metamorphism or rock production,” said O’Neilis. Metamorphic rock is the one that has been replaced with heat, pressure or other natural forces.
Instead, for a new study, O’Neilis appealed to the rare earth element samarium, which breaks down the neodymium of the element. It is a technique that has been used so far meteorites, as the elements were only active more than 4 billion years ago.
The Acasta Gneiss marks the boundary between Hadean Eon and the other department of the Earth History: Archean. – Library of Science and Society/Getty Images
“Disputes about age are that some people think that the clock we use is not good or has been influenced (other geological processes),” he said.
“This is a discussion about what we value on time, because we cannot use zirconium, and some people in my field will only convince the zirconians.”
O’Neil said that this technique is valuable in this case, as it is possible to measure the decomposition of two variants or isotopes into two different neodymium isotopes – basically getting two watches for one price. In the latest document, it was concentrated on a certain type of metamorphic ancient rock – metagabborne intrusion – taken from a belt, and two data points came in at the same age: 4.16 billion years.
This age, reached in the conclusion, meant that the “at least a small Hadean crust remaining” was preserved on the “Greenstone” belt, which would give invaluable insights into the origin of the Earth and how life was formed.
Rocks from the same place can retain various life signatures from eon, as well as microfosilia, small threads and tubes consisting of bacteria, noted Dominic Papineau, a senior scientist at the Institute of Govers of the China Academy of Science. He did not participate in recent research, but he studied fossils from the site.
“The rocks that have been newly outdated are from the mantle, which is believed to have no life or live for life,” said Papineau, who is also an honorary professor at the University of London College Markembry Biogeochemistry and Exobiology.
“However, it is now confirmed that adjacent sedimentary rock is at least 4,160 million years, which is only about 400 million years after the accumulation of our planet and solar system,” he added in an email.
“The evidence of very early life in these sedimentary rocks shows that the origin of life can occur very quickly (relatively speaking), which increases the likelihood that life in the universe is widespread and widespread in the universe.”
The debate is rested?
It is not yet clear whether the outcrops of “Nuvuagittu” will be widely recognized as the oldest rocks of the earth, other scientists who have not been related to research say.
Bernard Bourdon, a geochemist of the French Lyon Geology Laboratory, who previously took the earliest dates of the Navuagitti Greenstone Belt, said he was “more convinced” to the latest job and in previous studies he was “well improved”.
“Better compared to 2008 document is that both methods … They give the same age. That’s good. That’s what we criticized the first results,” said Bourdon, who is also a French research director of CNRS.
“After all, I think there is more reliability at the age,” he said, adding that he had some ‘small doubts’ and would like to investigate the data in more detail.
The age of the rock remains a “unresolved secret,” says Hugo Olierook, Geoscience of Australia’s Curtin University and Senior Researcher.
“If there are no ‘light’ minerals so far, they have turned to the whole berry that has a problem because all rock samples have several minerals,” Olierook said e-mail.
“It only needs one of these minerals to change, and their age to ‘rebuild’ younger age so that the entire card house can boil,” he added, noting that very high and low temperatures can naturally change mineral crystallization age in rock.
Jesse Reimink, Penn State University, Jesse Reimink, Professor of Early Career Professor at Rudy L. Slingerland, Penn State University, is very low when communicating with rock and minerals with a complex geological history that covers more than 4 billion years.
“Even if these rocks are only” 3.8 billion years old, it is quite wonderful that they are preserved. This current work provides more convincing data that supports 4.15 billion years ago, than the one who has been previously made, which has already been convincing, ”said Reimink.
“The times are so long, and the history of these rocks and minerals is so tortured that the collection of any primary information in total is quite wonderful.”
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