Earth's Continents Stabilized Due to Furnace-Like Heat, Study Reveals

"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."

"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. The processes that stabilized Earth's crust also mobilized rare earth elements-lithium, tin and tungsten-providing new clues for where to find them."

Stable continental crust formation required temperatures exceeding 900°C in the planet's lower continental crust. Very high temperatures enabled redistribution of radioactive elements such as uranium and thorium from deep to shallower levels. As those elements migrated upward they carried decay heat with them, allowing the deep crust to cool, strengthen and persist for billions of years. The same heat-driven processes mobilized and concentrated critical and rare-earth elements including lithium, tin and tungsten, producing new exploration targets. Comparable thermal and geochemical processes are likely on other Earth-like planets, linking continental stability to planetary habitability.

Read at State of the Planet