Continents loss to oceans boosts staying power

New research in the Proceedings of the National Academy of Science finds that the geological staying power of continents comes partly from their losing battle with the Earth's oceans over magnesium. Continents lose more than 20 percent of their initial mass to chemical weathering, but they ultimately gain because the lighter, silicon-rich rock that's left behind is more buoyant and less prone to being subducted and returned to the mantle.