Ruthenium-100 excesses in Hawaiian volcanic rocks gave Nils Messling’s team chemical evidence that some material crossed from Earth’s core into the mantle and later rose in a plume.
Nature-published measurements compared tiny ruthenium and tungsten isotope shifts—resolved at parts-per-million precision—and found the core was the most viable source for the Hawaiian signal.
Hawaii matters because its hotspot plume may rise from near the core-mantle boundary, but the study did not find gold moving through volcanoes or prove a direct molten pathway to the surface.
The result challenges the idea of a fully sealed boundary 2,900 kilometres down, yet it does not show a global leak: Réunion, Galápagos and Baffin Island samples lacked a clear anomaly.
For geologists, the significance is access rather than mining—volcanic rocks may preserve indirect samples of an otherwise unreachable interface deep inside Earth.