07 April 2014
Nature: The movement and collisions of Earth's tectonic plates have destroyed much of the evidence of their formation. David Bercovici of Yale University in New Haven, Connecticut, and his colleagues have created a computer model that presents a possible explanation for how they formed and when. The model begins with Earth having a solid crust as it is believed to have existed several billion years ago. A low-pressure area in the mantle caused one part of the crust to settle into the upper mantle. Convection in the mantle fractured the piece of crust and created subduction zones where the piece pushed against the rest of the crust. Over the span of one billion years, the process repeated several times, which created multiple tectonic plates. The model's prediction of the period when this occurred appears to match the timeline seen in mineral deposits formed in subduction zones.