At the core of a continent
Like lines in a deeply weathered face, the cracks and fissures in the Earth’s crust reveal a long and tumultuous lifetime. Massive continent-bearing plates have come together and broken apart, setting off earthquakes and volcanic eruptions that have fragmented underlying rock, changing the face of the planet over billions of years. Despite a geologically fractious history, Earth’s rigid outer layer, or lithosphere, retains ancient sections called cratons in which rocks have been left relatively undisturbed since they formed billions of years ago. These cratons typically occur at the center of continental landmasses, and contain some of Earth’s oldest rocks. How these cratons have survived on Earth’s surface, avoiding destruction by both plate-tectonic processes and erosion over billions of years, has been of interest to geologists for decades. In a new paper published today in Science, researchers at MIT have reconstructed the ancient history of the Wyoming Province, one of the...