Author: Chris Kirkland, Professor of Geochronology, Curtin University In the Pilbara of Western Australia, some of Earth’s oldest rocks lie beneath the sky, as they have for billions of years. They are dark, weathered volcanic rocks, close to 3.5 billion years old, cut by veins and stewed by deep time. Their survival is remarkable. Most rocks this old have moved back into Earth’s interior. These ones, still on the surface, have changed, but not enough to erase their first story.