Canada

Scientists have identified what could be the oldest rocks on Earth from a rock formation in Canada.

The Nuvvuagittuq Greenstone Belt has long been known for its ancient rocks — plains of streaked gray stone on the eastern shore of Hudson Bay in Quebec. But researchers disagree on exactly how old they are.

Work from two decades ago suggested the rocks could be 4.3 billion years old, placing them in the earliest period of Earth’s history. But other scientists using a different dating method contested the finding, arguing that long-ago contaminants were skewing the rocks’ age and that they were actually slightly younger at 3.8 billion years old.

In the new study, researchers sampled a different section of rock from the belt and estimated its age using the previous two dating techniques — measuring how one radioactive element decays into another over time. The result: The rocks were about 4.16 billion years old.