“For over 15 years, the scientific community has debated the age of volcanic rocks from northern Quebec,” says geoscientist Jonathan O’Neil<\/a> of the University of Ottawa in Canada.<\/p>\n “This confirmation positions the Nuvvuagittuq Belt as the only place on Earth where we find rocks formed during the Hadean eon.”<\/p>\n Related: <\/b>We May Have Found Earth’s Oldest Known Rock. It Was on The Moon<\/b><\/a><\/p>\n Earth’s surface and crust are always in motion. Tectonic forces<\/a> 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<\/a>.<\/p>\n 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<\/a>, before life managed to wriggle its way out of the primordial chemistry<\/a>.<\/p>\n 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<\/a>, how our planet formed, grew, and evolved can help us understand how to find similar planets<\/a> in the wider galaxy.<\/p>\n Nuvvuagittuq Greenstone Belt has long been eyeballed by scientists as one of these sites harboring Hadean<\/a> 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<\/a> and 2.7<\/a> billion years.<\/p>\n 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.<\/p>\n The most reliable isotope dating method we have relies on zircon crystals<\/a>. 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.<\/p>\n 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<\/a> and its decay products, isotopes of neodymium<\/a>. This is less reliable than uranium-lead dating.<\/p>\n 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<\/a> 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.<\/p>\n 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.<\/p>\n This result opens up exciting avenues for further research into our planet’s earliest days.<\/p>\n “Understanding these rocks is going back to the very origins of our planet,” O’Neil says<\/a>. “This allows us to better understand how the first continents were formed and to reconstruct the environment from which life could have emerged.”<\/p>\n![\"\"](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/06\/rocks-canada.jpg\")
Metagabbroic rock from the formation gives us a new date for its age. (Jonathan O’Neil)<\/p>\n![\"\"](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/06\/belt.jpg\")
Metagabbroic rock ripples through the Nuvvuagittuq Greenstone Belt. (Jonathan O’Neil)<\/p>\n![\"\"](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/06\/metagabbro.jpg\")
Detail of a metagabbroic intrusion. (Jonathan O’Neil)<\/p>\n