Within the Earth, blobs of molten iron on the move

New research by Yale University scientists suggests an explanation for the amount of iron in the Earth's largest interior layer, the mantle: migrating "iron-rich blobs" generated by chemical interactions in the zone between the planet's core and mantle. Scientists have long known of the core's rich iron content, but they have struggled to explain how the rocky mantle acquires iron in any abundance. The newly reported iron-enrichment process could also explain how other elements, such as platinum and hydrogen, get into the mantle, researchers said - attached to the iron. "Our work showed that there is a very efficient chemical interaction between the rocky part and the iron-rich part of Earth," said geophysicist Shun-ichiro Karato, professor of geology and geophysics at Yale and principal investigator of research published online Dec. 12 . "We've discovered a new mechanism by which a lot more iron from the Earth's core penetrates the mantle than previously thought possible, and a lot deeper into it. In the previous models, the penetration was limited to about one kilometer or less.