Earth's First Continents Sank Into The Planet Before Rising Up Again - ScienceAlert

A new examination of some of the oldest rocks in the world suggests that the first continents on Earth were unstable, and sank back into the mantle before making their way out again and reforming.

"The rocks in the core of the continents, called cratons, are more than three billion years old," explains geologist Fabio Capitanio of the Monash University School of Earth, Atmosphere and Environment in Australia.

"They formed in the early Earth and hold the secret to how continents and the planet changed over time.".

Given that continents are thought to be very important for the emergence and ongoing existence of life on Earth, figuring out how they formed has implications, not just for our own planet, but for the search for habitable worlds outside the Solar System.

And second, they tell us how the planets formed and changed in the past, including how the continents came to be and how they supported life, and how the atmosphere formed and changed as a result of the planets' tectonics."