Oldest rocks on Earth are in Quebec

WASHINGTON — A traveler walking along the eastern bank of Hudson Bay in northern Quebec can stand on the oldest bedrock known on Earth.

This ancient section of the planet’s crust may be as much as 4.28 billion years old, researchers report in today’s edition of the journal Science.

While the age of the Earth itself is estimated at 4.6 billion years, most of the original surface has been crushed and recycled through the movement of giant plates across the planet’s surface.

By measuring tiny variations in the chemical composition of the shore along Hudson’s Bay, researchers Jonathan O’Neil of McGill University in Montreal and Richard Carlson of the Carnegie Institution of Washington were able to date various rock samples to between 3.8 billion and 4.28 billion years ago.

Previously the oldest piece of bedrock was the Acasta Gneiss in Canada’s Northwest Territories, which is 4.03 billion years old.