Canadian scientists discover oldest rocks on Earth

WASHINGTON, September 26, 2008 (AFP) – The oldest rocks on Earth have been discovered in Canada, offering scientists a glimpse at the origins of the planet, announced scientists in a study to be published Friday.

The rocks, found in a belt of ancient bedrock in Quebec, are estimated to be 4.28 billion years old.

The find pushes back the age of the most ancient discovered remnants of the Earth’s crust by 300 million years.

“Our discovery (…) opens the door to further unlock the secrets of the Earth’s beginnings,” said Jonathan O’Neil, lead author of the study and a geologist at McGill University in Montreal, who collected and analyzed the rocks.

“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,” said O’Neil.

The rocks also suggest that continents formed very early in the Earth’s history, said Richard Carlson at the Carnegie Institution in Washington, co-author of the study, to be published in the September 26 edition of the journal Science.

Estimates of their age were made by measuring tiny variations in the isotopic composition of two “rare earth” elements, neodymium and samarium,