4.28 Billion Year Old Rock Vestige – Remnant of Earth’s Crust – Discovered in Canada

Researchers in Canada have found 4.28 billion year old rocks, probably the world’s oldest, and which may be remnants of a portion of the first crust that formed at the surface of our planet, known as the primordial crust.

The ancient rocks were found in Northern Quebec, along the Hudson’s Bay coast, 40 km south of Inukjuak in an area known as the Nuvvuagittuq greenstone belt.

The researchers who made the discovery estimated the age of the terrestrial rocks using isotopic dating, which analyzes the decay of the radioactive element, neodymium-142, contained within them, a technique that can only be used to date rocks roughly 4.1 billion years old or older.

The Earth is 4.6 billion years old, and remnants of its early crust are extremely rare – most of it has been mashed and recycled into Earth’s interior several times over by plate tectonics since the Earth formed.

The discovery team included McGill University earth scientists, Jonathan O’Neil and Don Francis teamed up with Richard W. Carlson, a researcher at the Carnegie Institution for Science in Washington, D.C., and Ross K. Stevenson, a professor at the Université du Québec à Montréal (UQAM).

The discovery, whose results are published in the September 26 issue of the journal Science, pushes back age of most ancient remnant of Earth’s crust by 300 million years, according to the researchers.

O’Neil said: “Our discovery not only opens the door to further unlock the secrets of the 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.”

Image credit: Poolie via Flickr under a Creative Commons license.