Weakened rock may explain the origin of plate tectonics, a simulation finds
The first ruptures in early Earth's skin formed because of the weakness of rock minerals merely a millimeter wide, two scientists propose. The small minerals’ behavior created boundaries defining Earth’s first crustal plates and set the stage for plate tectonics, according to a new computer simulation appearing April 6 in Nature.
Plate tectonics is special to Earth: The planet’s crust is divided into giant, mobile plates. A plate can bump up against another plate at a fault zone, or dive beneath one at a subduction zone. The outcome can be an earthquake or volcano. Where plates split apart, new crust forms. This occurs, for example, at the rift in the seafloor below the Atlantic Ocean. Venus, Earth’s near twin in size and composition, may once have had the conditions to start plate tectonic processes, but it didn’t.