Rare earth, Fe and Ti variations along the Galapagos spreading centre, and their relationship to the Galapagos mantle plume

Rare earths, Fe and Ti concentrations in basalts dredged along the Galapagos spreading centre reveal that a juvenile mantle plume is welling up beneath the Galapagos Islands and mixing with the depleted asthenosphere to the north-east and north-west beneath the ridge. Unusually extensive shallow-depth, crystal fractionation is also apparent on the ridge between 85 and 87°W. The ‘magnetic telechemistry’ hypothesis is further clarified.