craton
/ˈkreɪtɑn/
noun
- A large, stable block of the Earth's crust that forms the core of a continent and has remained relatively unchanged for billions of years.
- Geologists study cratons to understand the early history of our planet.
- Diamonds are often found in ancient cratons where deep volcanic pipes have brought them to the surface.
- The Canadian Shield is one of the oldest cratons on Earth.