For billions of years, Earth's continents have remained remarkably stable, forming the foundation for mountains, ecosystems and civilizations. But the secret to their stability has mystified scientists for more than a century. Now, a new study by researchers at Penn State and Columbia University provides the clearest evidence yet for how the landforms became and remained so stable - and the key ingredient is heat.
In a paper published today (Oct. 13) in the journal Nature Geoscience, the researchers demonstrated that the formation of stable continental crust - the kind that lasts billions of years - required temperatures exceeding 900 degrees Celsius in the planet's lower continental crust. Such high temperatures, they said, were essential for redistributing radioactive elements like uranium and thorium. The elements generate heat as they decay, so as they moved from the bottom to the top of the crust, they carried heat out with them and allowed the deep crust to cool and strengthen.
The implications of the discovery go beyond geology, the researchers said, to open avenues for modern applications such as exploration for critical minerals - which are essential for modern technologies like smartphones, electric vehicles and renewable energy systems - and the search for habitable planets.
