A craton’s clues to Earth’s moving plates

Studies in Australia push the date back to 3.2 billion years.

A geologic map of the 500-kilometre Pilbara Craton in Western Australia, with lavas shown in green. The rocks exposed here range from 2.5 to 3.5 billion years old. Credit: Alec Brenner, Harvard University. Map data from the Geological Survey of Western Australia.