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Yahoo
12 hours ago
- Science
- Yahoo
Earth's oldest rocks date back 4.16 billion years
While rocks are not exactly living things, they are not immune to Earth's fury. Ever-shifting tectonic plates constantly devour and pulverize them, or some rocks get turned into diamonds from the immense pressure underneath our feet. While life on Earth has almost been wiped out at least five times, some rocks pre-date life on Earth and have stood the ultimate test of time. Gray rocks uncovered in northern Nunavik, Quebec, Canada may be the ultimate primordial find. The stones date back 4.16 billion years to the Hadean era and are the oldest known rocks on the planet. They are described in a study published June 26 in the journal Science. Earth was a ball of molten lava when it first formed about 4.5 billion years ago. Scientists originally believed that Earth's first eon–the Hadean–ended when the first rocks formed. A golden spike–a geological marker indicates a boundary between time periods–that ended the Hadean eon is about 4.03 billion years old and located in Canada's Northwest Territories. The Nuvvuagittuq Greenstone Belt, located over 1,000 miles southeast of the Hadean's golden spike, has long been known for its ancient rocks. However, researchers have disagreed about the true age of these plains of gray stone that line the eastern shore of Hudson Bay in Quebec. In 2008, researchers proposed that these rocks dated back 4.3 billion years. Other scientists using a different dating method contested, saying that contaminants from ages ago were altering the rocks' age and they were only 3.8 billion years old. 'For over 15 years, the scientific community has debated the age of volcanic rocks from northern Quebec,' study co-author and University of Ottawa geologist Jonathan O'Neill said in a statement. 'Our previous research suggested that they could date back 4.3 billion years, but this wasn't the consensus.' [ Related: How old is Earth? It's a surprisingly tough question to answer. ] This new study used rock samples from a different part of the Nuvvuagittuq Greenstone Belt. The samples were collected in 2017 near the municipality of Inukjuak, Nunavik, by study co-author Christian Sole, while was completing his Master's degree. To determine the age of these rocks, the team combined geochemistry with petrology–a branch in geology that focuses on the composition, texture, and structure of rocks and the conditions under which they form. They also applied two radiometric dating methods to see how radioactive isotopes of the elements samarium and neodymium change over time. [ Related: Ancient rocks tie Roman Empire's collapse to a mini ice age. ] They found that both chronometers indicated that the rocks are 4.16 billion years old. Since the planet Earth formed roughly 4.5 billion years ago, this puts the rocks within a few hundred million years of our planet's earliest day–somewhat close in geological time. Typically, primordial rocks like these are melted and used over and over again by Earth's moving tectonic plates. While scientists uncovered some 4 billion-year-old rocks in Canada's Acasta Gneiss Complex, finding them at the surface is not common. According to the team, this discovery opens a unique window on the early Earth, potentially offering up clues to its existence. 'Understanding these rocks is going back to the very origins of our planet,' O'Neill said. 'This allows us to better understand how the first continents were formed and to reconstruct the environment from which life could have emerged.'
CBS News
a day ago
- 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
a day ago
- 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.'
CBS News
a day ago
- Science
- CBS News
What may be Earth's oldest rocks found in Canada
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."
CTV News
a day ago
- Science
- CTV News
Rocks found on Quebec shoreline found to be the oldest on Earth
A Telecommunications tower is seen in the village of Inukjuak on the shore of Hudson Bay Thursday, May 12, 2022 in Inukjuak, Quebec. THE CANADIAN PRESS/Adrian Wyld Along the eastern shore of Hudson Bay in Canada's northeastern province of Quebec, near the Inuit municipality of Inukjuak, resides a belt of volcanic rock that displays a blend of dark and light green colors, with flecks of pink and black. New testing shows that these are Earth's oldest-known rocks. Two different testing methods found that rocks from an area called the Nuvvuagittuq Greenstone Belt in northern Quebec date to 4.16 billion years ago, a time known as the Hadean eon. The eon is named after the ancient Greek god of the underworld, Hades, owing to the hellish landscape thought to have existed then on Earth. The research indicates that the Nuvvuagittuq Greenstone Belt harbors surviving fragments of Earth's oldest crust, the planet's outermost solid shell. The Nuvvuagittuq rocks are mainly metamorphosed volcanic rocks of basaltic composition. Metamorphosed rock is a kind that has been changed by heat and pressure over time. Basalt is a common type of volcanic rock. The rocks tested in the new study were called intrusions. That means they formed when magma - molten rock - penetrated existing rock layers and then cooled and solidified underground. The researchers applied two dating methods based on an analysis of the radioactive decay of the elements samarium and neodymium contained in them. Both produced the same conclusion - that the rocks were 4.16 billion years old. Future chemical analyzes of these rocks could provide insight into Earth's conditions during the Hadean, a time shrouded in mystery because of the paucity of physical remains. 'These rocks and the Nuvvuagittuq belt being the only rock record from the Hadean, they offer a unique window into our planet's earliest time to better understand how the first crust formed on Earth and what were the geodynamic processes involved,' said University of Ottawa geology professor Jonathan O'Neil, who led the study published on Thursday in the journal Science. The rocks may have formed when rain fell on molten rock, cooling and solidifying it. That rain would have been composed of water evaporated from Earth's primordial seas. 'Since some of these rocks were also formed from precipitation from the ancient seawater, they can shed light on the first oceans' composition, temperatures and help establish the environment where life could have begun on Earth,' O'Neil said. Until now, the oldest-known rocks were ones dating to about 4.03 billion years ago from Canada's Northwest Territories, O'Neil said. While the Nuvvuagittuq samples are now the oldest-known rocks, tiny crystals of the mineral zircon from western Australia have been dated to 4.4 billion years old. The Hadean ran from Earth's formation roughly 4.5 billion years ago until 4.03 billion years ago. Early during this eon, a huge collision occurred that is believed to have resulted in the formation of the moon. But by the time the Nuvvuagittuq rocks formed, Earth had begun to become a more recognizable place. 'The Earth was certainly not a big ball of molten lava during the entire Hadean eon, as its name would suggest. By nearly 4.4 billion years ago, a rocky crust already existed on Earth, likely mostly basaltic and covered with shallow and warmer oceans. An atmosphere was present, but different than the present-day atmosphere,' O'Neil said. There had been some controversy over the age of Nuvvuagittuq rocks. As reported in a study published in 2008, previous tests on samples from the volcanic rock layers that contained the intrusions yielded conflicting dates - one giving an age of 4.3 billion years and another giving a younger age of 3.3 to 3.8 billion years. O'Neil said the discrepancy may have been because the method that produced the conclusion of a younger age was sensitive to thermal events that have occurred since the rock formed, skewing the finding. The new study, with two testing methods producing harmonious conclusions on the age of the intrusion rocks, provides a minimum age for the volcanic rocks that contain these intrusions, O'Neil added. 'The intrusion would be 4.16 billion years old, and because the volcanic rocks must be older, their best age would be 4.3 billion years old, as supported by the 2008 study,' O'Neil said. Reporting by Will Dunham in Washington, Editing by Rosalba O'Brien, Reuters
