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Canadian bedrock more than 4 billion years old may be the oldest known section of the Earth's early crust.
Scientists at the Carnegie Institution of Washington and McGill University in Montreal used geochemical methods to obtain an age of 4.28 billion years for samples of the rock, making it 250 million years more ancient than any previously discovered rocks.
The findings, which offer scientists clues to earliest stages of our planet's evolution, are published in this week's issue of the journal Science.