Back When the Planet Had Just One Plate - Science Friday
As magma oceans began to cool on a very early earth, a solid shell formed on the planet’s surface above the still-molten mantle. However, the exact mechanics of how that proto-Earth was transformed from its ancient state to the world of shifting tectonic plates we see today are still a mystery. In a report published in the journal Nature, geologist Michael Brown and colleagues describe efforts to model how different mineral combinations react at specific combinations of temperature and pressure. That model, Brown says, shows that the modern plate tectonic process of subduction may not have been needed to form some of the world’s oldest rocks.