Latest news with #oldestrocks
Yahoo
3 hours ago
- 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.'
Yahoo
a day ago
- Science
- Yahoo
Rocks in Canada's Quebec province found to be the oldest on Earth
By Will Dunham (Reuters) -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 analyses 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.
BBC News
2 days ago
- 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
2 days 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."
CBS News
2 days 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."
