Hawaii rocks reveal a faint signal from Earth’s core crossing into the mantle
A 2025 ruthenium-isotope study of Hawaiian basalts finds a small core-derived signal in the mantle, suggesting material from Earth’s core can cross the core–mantle boundary and reach surface plume systems. This supports long-standing ideas of core–mantle exchange but does not show direct transport of gold or imply a large, exploitable flux. The finding adds nuance to the notion that the core is sealed, and while it aligns with estimates that the core holds most of Earth’s gold (enough, in old calculations, to coat continents in a 0.5 m layer), the signal is tiny and more measurements from Hawaii and other hotspots are needed to gauge its extent.
