Latest news with #ChristianSole
Yahoo
15 hours ago
- Science
- Yahoo
4-Billion-Year-Old Stripey Rocks in Canada May Be The Oldest on Earth
A belt of swirly, stripey rock in the northeast reaches of Canada looks like it contains some of the oldest minerals ever found on our planet's surface. A new dating analysis of minerals in the Nuvvuagittuq Greenstone Belt suggests that parts of the formation could be as old as 4.16 billion years – nearly as old as the planet's 4.54-billion-year age. The results mean that the belt represents one of the best sites for understanding our planet's infancy. "For over 15 years, the scientific community has debated the age of volcanic rocks from northern Quebec," says geoscientist Jonathan O'Neil of the University of Ottawa in Canada. "This confirmation positions the Nuvvuagittuq Belt as the only place on Earth where we find rocks formed during the Hadean eon." Related: We May Have Found Earth's Oldest Known Rock. It Was on The Moon Earth's surface and crust are always in motion. Tectonic forces from below and weathering influences from above mean that the planet's surface is constantly in flux. For surface features to survive for billions of years is unusual. Places where ancient minerals have managed to somehow survive the ravages of time are very scientifically valuable. They can tell us what our planet was like as it was forming, before life managed to wriggle its way out of the primordial chemistry. This has far-reaching implications far beyond our own tiny blue world: since Earth is the only planet on which we know for a fact life exists, how our planet formed, grew, and evolved can help us understand how to find similar planets in the wider galaxy. Nuvvuagittuq Greenstone Belt has long been eyeballed by scientists as one of these sites harboring Hadean minerals, from the first of Earth's four geological eons, spanning the time of its formation until just over 4 billion years ago. However, previous attempts at dating minerals thought to be ancient returned confusing and inconsistent results, ranging between around 4.3 and 2.7 billion years. Led by geoscientist Christian Sole of the University of Ottawa, a team of researchers decided to try a different approach. Previous tests had measured the ratios of radioactive atoms and the isotopes of their decay products in the basaltic rock. The most reliable isotope dating method we have relies on zircon crystals. When it is forming, zircon takes up trace amounts of uranium, but strongly rejects lead. Over time, the uranium decays into lead inside the zircon; so any lead in a zircon crystal has to be from the radioactive decay of uranium. Because we precisely know the decay rate of uranium, the ratios can be used to precisely date the zircon. Basaltic rock, like the Nuvvuagittuq Greenstone Belt, presents challenging conditions for the formation of zircon, so many previous measurements relied on ratios of radioactive samarium and its decay products, isotopes of neodymium. This is less reliable than uranium-lead dating. Sole and his colleagues took a new tack. They focused on large inclusions of metagabbro, a type of rock that was originally an igneous rock called gabbro that metamorphosed under heat and pressure inside the planet's crust. These metagabbros intruded on older basalts, so they provide a minimum age for the surrounding basalt matrix. The team subjected their samples to both lead-uranium and samarium-neodymium dating. Both forms of analysis yielded the same result, even for rocks of different mineral compositions taken from different locations: the minimum age for the Nuvvuagittuq Greenstone Belt is 4.16 billion years. This result opens up exciting avenues for further research into our planet's earliest days. "Understanding these rocks is going back to the very origins of our planet," O'Neil says. "This allows us to better understand how the first continents were formed and to reconstruct the environment from which life could have emerged." The research has been published in Science. Scientific First: Mice With Two Fathers Now Have Offspring 'Zombie' Fungus Caught Bursting From Host Bodies 99 Million Years Ago 100-Million-Year-Old Rock Reveals 40 Never-Before-Seen Squid Species
Forbes
18 hours ago
- Science
- Forbes
New Study Confirms That The Oldest Rocks On Earth Are Canadians
Iron-rich chert from the Nuvvuagittuq Supracrustal Belt, Québec, Canada, containing tubular and ... More filamentous microfossils. A team of Canadian and French researchers has confirmed that Nunavik/Quebec in Northern Canada is home to the oldest known rocks on Earth, dating back over 4.16 billion years. The rocks of the Nuvvuagittuq Greenstone Belt, a rock formation preserved in a fold of the Canada shield, are believed to be over 4.3 billion years old, forming just 200 million years after Earth formed. They include the oldest known examples of sheeted dikes and pillow basalts. Such a succession of volcanic rocks is typically found in a spreading zone of a mid oceanic ridge, forming today Earth's oceanic crust. However, since first age estimates were published over 20 years ago, Various phases of tectonic deformation and chemical alteration makes it difficult to find pristine rock samples. There are also uncertainties involving the applied methods used at the time to date the rocks. In a new study, researchers sampled a new section of the greenstone belt, using modern dating methods they confirmed the high age of the entire formation. Samples were collected in 2017 near the municipality of Inukjuak, Nunavik, as part of Christian Sole's thesis, who completed a master's at the University of Ottawa in 2021. After preliminary analysis, additional work was carried out at the University of Ottawa and Carleton University, to confirm the age of the rocks. First age estimates were based on volcanic rocks — deposited as lava flows on the bottom of an ancient ocean — chemically altered as they came into contact with water. The researches focused on magmatic rocks, rocks crystallized before reaching the surface. Radioactive elements are trapped in the forming crystals, slowly decaying providing a natural timer for the rock's formation age. From left: Christian Sole, Professor Hanika Rizo and Professor Jonathan O'Neil collecting rock ... More samples. To establish the age of these rocks, the researchers combined petrology and geochemistry and applied two radiometric dating methods using different isotopes of the elements samarium and neodymium. The new dates 'gave exactly the same age,' says study author Jonathan O'Neil, University of Ottawa, in an interview to AP. The current study shows that dikes of magmatic rocks crossing these volcanic formations are 4.16 billion years old, which confirms that the volcanic rocks must be older, and thus, that this region of the Canadian north is indeed home to the oldest known rocks on Earth. 'Understanding these rocks is going back to the very origins of our planet. This allows us to better understand how the first continents were formed and to reconstruct the environment from which life could have emerged,' concludes O'Neil. The study,"Evidence for Hadean mafic intrusions in the Nuvvuagittuq Greenstone Belt, Canada," was published in the journal Science. Additional material and interviews provided by the University of Ottawa.
