World’s oldest rocks discovered in Canada (Lead)September 26th, 2008 - 11:34 pm ICT by IANS
Toronto, Sep 26 (IANS) Canadian researchers have discovered the world’s oldest rocks in the country’s Quebec province that could shed more light on our planet’s mysterious beginnings.Estimated to be 4.28 billion years old, the rocks were discovered along the Hudson’s Bay coast in the Nuvvuagittuq Greenstone belt.
The new discovery by researchers at McGill University in Montreal pushes back the age of most ancient rocks by 300 million years, they said in a study published in the journal Science Friday.
The researchers said the rocks, known as ‘faux-amphibolites’, might be remnants of earth’s primordial crust which was first formed at the surface of the planet.
They determined the age of the rocks by using isotopic dating, which analyses the decay of the radioactive element neodymium-142 contained within them. This technique can only be used to date rocks roughly 4.1 billion years old or older.
But this is the first time it has ever been used to date terrestrial rocks, because nothing this old has ever been discovered before, a university statement said.
The data from these findings will give researchers a new window on the early separation of the earth’s mantle from the crust in the Hadean Era, said Jonathan O’Neil, lead author of the study and a geologist at the university.
“Our discovery not only opens the door to further unlock the secrets of earth’s beginnings. Geologists now have a new playground to explore how and when life began, what the atmosphere may have looked like, and when the first continent formed,” he said.
The discovery was made in collaboration with the Carnegie Institution for Science in Washington and the local Université du Québec à Montréal (UQAM).