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Yahoo
06-07-2025
- Science
- Yahoo
World's Oldest Rocks Confirmed in Canada
On the shores of Hudson Bay in northeastern Canada lie what could be the world's oldest rocks. A study now suggests they are at least 4.16 billion years old — 160 million years older than any others recorded, and the only piece of Earth's crust known to have survived from the planet's earliest eon. In 2008, researchers reported that these rocks dated back 4.3 billion years, a claim that other scientists contested. Work reported today in Science1 seems to confirm that the rocks, known as the Nuvvuagittuq Greenstone Belt, are record-breakers. Researchers say the rock formation offers a unique window into early Earth, after the planet cooled from its fiery birth 4.5 billion years ago. [Sign up for Today in Science, a free daily newsletter] 'It's not a matter of 'my rock is older than yours',' says Jonathan O'Neil, a geologist at Ottawa University who leads the research team. 'It's just that this is a unique opportunity to understand what was going on during that time.' The 'oldest rocks' label has sometimes backfired. In the past few years, other teams have chiselled many samples out of the Nuvvuagittuq belt, leaving the landscape scarred. Last year, the local Inuit community closed access to the rocks to prevent further despoliation. Only a handful of geological samples in the world date back to 3.8 billion years or older. Of those, the oldest undisputed rocks are found in the Acasta gneiss formation in Canada's Northwest Territories; at 4 billion years old, they mark the boundary between Earth's first geological eon, the Hadean, and the following one, the Archaean. Geologists have also found tiny mineral crystals dating back to the Hadean — such as 4.4-billion-year-old zircon crystals from Western Australia — that have become embedded into newer rock. But there are no known surviving chunks of crust from the Hadean — except, perhaps, the Nuvvuagittuq Greenstone Belt. It consists primarily of material that started out as volcanic basalt before undergoing various modifications during Earth's tortured history. In their 2008 work, O'Neil and his colleagues analysed the chemical imprint left by the radioactive decay of the isotope samarium-146 into neodymium-142 to calculate that the Nuvvuagittuq rocks were 4.3 billion years old. (Samarium-146 is a short-lived isotope that was depleted in Earth's first 500 million years, and none was left after about 4 billion years ago.) Other scientists challenged that work, arguing, for instance, that Hadean-age crust had become mixed into younger crust, contaminating the results. For the latest work, O'Neil's team analysed some once-molten rocks that had intruded into the main Nuvvuagittuq rocks like a knife cutting into a cake. By dating the intruded rocks, O'Neil and his colleagues were able to establish a minimum age for the cake itself. They used two radioactive clocks: the decay of samarium-146 into neodymium-142 and that of samarium-147 into neodymium-143. Both yielded ages of around 4.16 billion years for the intruded rocks. 'If you don't agree with this, then you need a very speculative, intricate model to get to the same answer,' says O'Neil. Having both clocks agree on an age — which wasn't the case in the earlier work — strengthens the case for a Hadean age for the rocks, says Bernard Bourdon, a geochemist at the University of Lyon in France. He remains circumspect, though, and says he would like to see additional lines of evidence, involving other radioactive isotope decays. 'I would be happy if these rocks were truly Hadean, but I think we still need to be cautious,' Bourdon says. The paper 'provides a new data set that hopefully can advance this discussion', says Richard Carlson, a geochemist at Carnegie Science in Washington DC who has collaborated with O'Neil in previous work. To Carlson, the bulk of the evidence suggests that the rocks are indeed Hadean. For now, more answers might have to wait. The Pituvik Landholding Corporation in Inukjuak, Canada — the Inuit group that is steward of the land in question — is not currently granting permits for further scientific study, due to the earlier damage by other groups. 'It's unfortunate, but I would do the same,' O'Neil says. This article is reproduced with permission and was first published on June 26, 2025.
Yahoo
29-06-2025
- Science
- Yahoo
Obscure rock formation in Canada may contain the world's oldest minerals
When you buy through links on our articles, Future and its syndication partners may earn a commission. An obscure rock formation on the eastern shore of Canada's Hudson Bay may contain the oldest known rocks on Earth, a new study claims. The analysis dated the site's streaky gray rocks, part of an outcrop called the Nuvvuagittuq Greenstone Belt, to 4.16 billion years ago — meaning they're remnants from our 4.57 billion-year-old planet's earliest crust. The dating, performed by two methods that used the decay of radioactive isotopes (versions of elements) to measure the age of ancient magma trapped inside the rocks, significantly bolsters a controversial past study by the same scientists. If their findings, published June 26 in the journal Science, stand up, they could offer a unique window into our planet's ancient history and the geochemical stage where life emerged. "The volcanic rocks have to be at least 4.16 billion years old or older; I would argue that the best age for them is 4.3 billion years old," study co-author Jonathan O'Neil, a professor of environmental science at the University of Ottawa, told Live Science. "No known rocks are older." Earth began as a ball of red-hot lava. It slowly cooled over its first 600 million years, known as the Hadean eon, when pockets of solid rock started to form. This was a tumultuous time for our young planet, which was repeatedly pummeled by asteroids and even sustained a cataclysmic blow from the protoplanet Theia, which tore off a chunk of Earth to form our moon. Related: Did plate tectonics give rise to life? Groundbreaking new research could crack Earth's deepest mystery Then, as early as 3.8 billion years ago, Earth's surface splintered into tectonic plates, which dived beneath each other to be recycled into Earth's interior or to build up vast mountain ranges or trenches. This subduction means that many of the rocks on our planet's surface have long been chemically altered by intense heat and pressure. Yet some regions are far enough from tectonic plate boundaries to contain rocks that have remained unchanged for billions of years. One of these is in northeastern Canada, and its most ancient part is the Nuvvuagittuq Greenstone Belt (NGB). Scientists agree that this outcrop is at least 3.8 billion years old. Then, in 2008, O'Neil and his colleagues published a study suggesting that the NGB was 4.3 billion years old — which would mean it contained the oldest rocks in the world. But other geologists objected, suggesting there were flaws in the researchers' methods. Old rocks are typically dated using a mineral called zircon, which is chemically stable over billions of years. The volcanic rocks in the NGB, however, don't contain zircon, which forced the scientists to measure the rocks' age by the decay of the element samarium into neodymium. Yet trouble lurked within this new method. Samarium can decay into neodymium through two pathways (samarium-146 into neodymium-142, or samarium-147 into neodymium-143), creating two isotopic clocks with different decay speeds. The first decay path leads to a half-life — the period of time required for half the original element to remain — of about 96 million years, while the second pathway has a half-life spanning trillions of years. This means that the two decay pathways produced wildly different estimates for the ages of the rocks. This is because with the longer-lived clock ticking to the present day, it is especially susceptible to tectonic events muddling its isotopes part way through the decay process. "Any 'cooking' of the rocks or metamorphism after 4 billion years ago won't really affect that short-lived clock but can reset the long-lived clock and cause the age difference between these two systems," O'Neil said. RELATED STORIES —Hidden 36 million-year-long cycles may fuel biodiversity on Earth, ancient rocks reveal —Zealandia, Earth's hidden continent, was torn from supercontinent Gondwana in flood of fire 100 million years ago —Is Africa splitting in two? To sidestep this issue, the team went back to the formations to search for sections where magma from Earth's mantle, or middle layer, intruded into the planet's primordial crust. Because these intrusions had to be younger than the rock they seeped into, they could be used as a minimum age. The new analysis revealed that within these sections of the NGB, both samarium to neodymium decays offered the same age: 4.16 billion years. If further research does confirm that the rocks are as old as O'Neil's team believes, they could offer vital insight into how life emerged on our planet and potentially beyond it. "Some rocks from the Nuvvuagittuq Greenstone Belt were formed by precipitation from seawater, and these can help understand the composition of our first oceans, their temperature, perhaps the atmosphere and also could host the oldest traces of life on Earth," O'Neil said. "Understanding the environment where life could have started on our planet also helps in our quest to find traces of life elsewhere, such as Mars.'
BBC News
27-06-2025
- Science
- BBC News
Oldest rocks in the world are in Canada scientists say
Scientists think they have found the oldest rocks on ancient rocks were found in the Nuvvuagittuq Greenstone Belt, in Quebec in Canada, and for the last two decades scientists have been studying they hadn't been able to agree on an accurate age for the rocks, until teams using two different dating methods had produced different ages for the rocks: 4.3 billion and 3.8 billion years the latest study says the rocks are actually 4.16 billion years old! How did scientists test the old rocks? The scientists used both the techniques from previous tests, but focussed in on just one type of rock that made up the stripy stones. This type of stone is called metagabbro and is a rock that formed under huge heat and pressure inside the planet's crust billions of years tests brought back the same result this time - the rock was 4.16 billion years rocks are from one of the earliest periods on Earth, known as the Hadeon Earth was formed around 4.5 billion years ago and rocks from this time are an incredibly rare, as the movement of the Earth's tectonic plates mean that many have been melted and O'Neil, who led the study in the Science journal said the rocks give a "unique window into our planet's earliest time to better understand how the first crust formed on Earth".He added that because some were formed through ancient seawater, they shed light on the first oceans and "help established the environment where life could have begun on Earth."
CBS News
27-06-2025
- Science
- CBS News
These may be the oldest rocks on Earth
Scientists have identified what could be the oldest rocks on Earth from a rock formation in Canada. The Nuvvuagittuq Greenstone Belt has long been known for its ancient rocks - plains of streaked gray stone on the eastern shore of Hudson Bay in Quebec. But researchers disagree on exactly how old they are. This photo provided by researcher Jonathan O'Neil shows the landscape at the Nuvvuagittuq Greenstone Belt in northeastern Canada. Jonathan O'Neil / AP Dispute apparently settled Work from two decades ago suggested the rocks could be 4.3 billion years old, placing them in the earliest period of Earth's history. But other scientists using a different dating method contested the finding, arguing that long-ago contaminants were skewing the rocks' age and that they were actually slightly younger — at 3.8 billion years old. In the new study, researchers sampled a different section of rock from the belt and estimated its age using the previous two dating techniques - measuring how one radioactive element decays into another over time. The result: The rocks were about 4.16 billion years old. The different methods "gave exactly the same age," said study author Jonathan O'Neil with the University of Ottawa. The new research was published Thursday in the journal Science. This photo provided by researcher Jonathan O'Neil shows an outcropping of about 4.16 billion year old rocks at the Nuvvuagittuq Greenstone Belt in northeastern Canada, with a knife to indicate scale. Jonathan O'Neil / AP Ancient rocks could shed light on Earth's earliest days Earth formed about 4.5 billion years ago from a collapsing cloud of dust and gas soon after the solar system existed. Primordial rocks often get melted and recycled by Earth's moving tectonic plates, making them extremely rare on the surface today. Scientists have uncovered 4 billion-year-old rocks from another formation in Canada called the Acasta Gneiss Complex, but the Nuvvuagittuq rocks could be even older. Studying rocks from Earth's earliest history could give a glimpse into how the planet may have looked - how its roiling magma oceans gave way to tectonic plates - and even how life got started. "To have a sample of what was going on on Earth way back then is really valuable," said Mark Reagan with the University of Iowa, who studies volcanic rocks and lava and was not involved with the new study. This photo provided by researcher Jonathan O'Neil shows a closeup of a rock from Canada's Nuvvuagittuq Greenstone Belt dated to about 4.16 billion years old. Jonathan O'Neil / AP Inuit community wants steps to avoid rocks being exploited The rock formation is on tribal Inukjuak lands and the local Inuit community has temporarily restricted scientists from taking samples from the site due to damage from previous visits. After some geologists visited the site, large chunks of rock were missing and the community noticed pieces for sale online, said Tommy Palliser, who manages the land with the Pituvik Landholding Corp. The Inuit community wants to work with scientists to set up a provincial park that would protect the land while allowing researchers to study it. "There's a lot of interest for these rocks, which we understand," said Palliser, a member of the community. "We just don't want any more damage."
CNN
27-06-2025
- Science
- CNN
Scientists say they have identified Earth's oldest rocks. It could reveal an unknown chapter in our planet's history
A rocky outcrop in a remote corner of northern Quebec appears serene in its eerie isolation on the eastern shore of Canada's Hudson Bay. But over the past two decades, this exposed remnant of ancient ocean floor, known as the Nuvvuagittuq Greenstone Belt, has been a heated scientific battleground in the quest to identify Earth's oldest rock. New research suggests that the geological site harbors the oldest known surviving fragments of Earth's crust, dating back to 4.16 billion years ago. It's the only rock determined to be from the first of four geological eons in our planet's history: the Hadean, which began 4.6 billion years ago when the world was hot, turbulent and hell-like. 'Rocks are books for geologists … and right now we're missing the book (on the Hadean). The Nuvvuagittuq Greenstone Belt would be at least one page of that book, so that's why it's so important,' said geologist Jonathan O'Neil, author of the research published Thursday in the journal Science. The Nuvvuagittuq Greenstone Belt has been dated several times by different research groups, with widely divergent results. Most agree the rock is at least 3.75 billion years old — but that wouldn't make it Earth's oldest. The Acasta Gneiss Complex, a group of rocks exposed along a riverbank nearly 200 miles (300 kilometers) north of Yellowknife, in northwestern Canada, is more widely agreed to be the planet's oldest geological formation. These rocks are unambiguously dated at 4.03 billion years old, marking the boundary between the Hadean Eon and the next chapter in Earth's history: the Archean. (There are older rocks on the planet — but not from the planet — that aren't part of this debate: Some meteorites are 4.5 billion years old.) A controversial 2008 paper coauthored by O' Neil, who has been studying the site since he was a doctoral student, argued Nuvvuagittuq Greenstone Belt was 4.3 billion years old; however, other geologists took issue with the limits of the dating techniques and how the data was interpreted. With this latest paper, O'Neil, now an associate professor at the University of Ottawa in the department of Earth and environmental sciences, aims to prove his critics wrong. Dating rocks involves using radiometric techniques that harness the natural and spontaneous radioactive decay of certain elements in the rock, which acts as a type of clock. O'Neil uses an hourglass analogy: Imagine counting grains of sand at the top (radioactive elements) and bottom (elements produced from radioactive decay). Knowing the speed of the flowing grains (which represents the decay rate), allows scientists to date rocks. Some of these radiometric clocks are robust and can withstand the high temperatures and pressures Earth's crust has endured over the eons, while others are more affected by these processes. The gold standard and easiest way to date very old rock formations is with a very tough mineral known as a zircon. These tiny crystals incorporate a bit of uranium into their structure, and researchers can pinpoint their age by measuring the radioactive decay of uranium atoms, which turn into lead at a known rate. However, the Nuvvuagittuq Greenstone Belt — which was mapped after a geological survey in the 1960s but first attracted scientific attention in the early 2000s — contains very few rocks bearing zircons as they rarely occur in specimens with lower levels of silicon, including ones that were once ancient ocean crust. 'We tried to find zircons. They're just not there, or formed at a later time during the metamorphism or cooking of the rocks,' O'Neil said. Metamorphic rock is that which has been transformed by heat, pressure or other natural forces. Instead, for the new study, O'Neil turned to the rare earth element samarium, which decays into the element neodymium. It's a technique that has been used to date meteorites because the elements were only active more than 4 billion years ago. 'The controversy about the age is that some people believe the clock we use is not good or it was affected (by other geological processes),' he said. 'It's a debate about what exactly we are measuring in time because we can't use zircon, and some people in my field would only be convinced by zircons.' O'Neil said the technique was valuable in this case because it's possible to measure the decay of two variants, or isotopes, of samarium into two distinct isotopes of neodymium — essentially getting two clocks for the price of one. The latest paper focused on a specific type of metamorphic ancient rock — metagabbroic intrusions — sampled from within the belt, and the two data points converged on the same age: 4.16 billion years old. This age, the study concluded, meant that 'at least a small remnant' of Hadean crust was preserved in the Nuvvuagittuq Greenstone Belt, which would provide invaluable insights into Earth's origins and how life formed. Nearby rocks from the same location may preserve various signatures of life from the eon, as well as microfossils, tiny filaments and tubes formed by bacteria, noted Dominic Papineau, a senior research scientist at the Institute of Deep-sea Science and Engineering at the Chinese Academy of Sciences. He wasn't involved in the latest research but has studied fossils from the site. 'The rocks that were newly dated come from the mantle, which is not thought to harbour life or be habitable for life,' said Papineau, who is also an honorary professor of Precambrian biogeochemistry and exobiology at the University College London. 'However, the adjacent sedimentary rocks are now confirmed to be at least 4,160 million years old, which is 'only' about 400 million years after the accretion of our planet and of the Solar System,' he added in an email. 'Evidence of very early life in these sedimentary rocks indicate that the origin of life can take place very quickly (relatively speaking), which increases the probability that life is common and widespread in the universe.' It's not yet clear whether Nuvvuagittuq outcrops will become widely accepted as Earth's oldest rocks, according to other scientists who were not involved with the research. Bernard Bourdon, a geochemist at the Lyon Geology Laboratory in France who had previously taken issue with the earliest dates for Nuvvuagittuq Greenstone Belt published by O'Neil, said he was 'more convinced' by the latest work, and it was 'well improved' on previous studies. 'What is better, compared to the 2008 paper, is the fact that the two techniques … they give the same age. That's good. That's where we criticized the first results,' Bourdon, who is also research director at French scientific research body CNRS, said. 'In the end, I think there's more credibility to the age,' he said, adding that he had some 'small doubts' and would like to investigate the data more in depth. The age of the rocks 'remains an unsolved mystery,' according to Hugo Olierook, a geoscientist and senior research fellow at Curtin University in Australia. 'In the absence of 'easy' minerals to date, they have turned to whole-rock, which is fraught with problems as whole-rock samples have multiple minerals,' Olierook said via email. 'It only takes one of these minerals to have been altered and their age 'reset' to a younger age for the whole house of cards to fall over,' he added, noting that very high and low temperatures can naturally alter the crystallization age of minerals in rock. Very little is definitive when dealing with rocks and minerals that have complex geological histories spanning more than 4 billion years, according to Jesse Reimink, the Rudy L. Slingerland Early Career Professor of Geoscience at Penn State University. 'Even if these rocks are 'only' 3.8 billion years old, it is quite amazing that they are preserved. This current work presents more compelling data, supporting an age of 4.15 billion years ago, than that which was previously produced, which was already compelling,' Reimink said. 'The timescales are so long, and the history of these rocks and minerals is so tortured, that gleaning any primary information from them at all is pretty amazing.'
