Partial melting of Earth's mantle generates oceanic crust and leaves behind a chemically
depleted residual mantle. The time-integrated composition of this chemically depleted
mantle is generally inferred from basalts produced at mid-ocean ridges. However, isotopic
differences between oceanic mantle rocks and mid-ocean ridge basalts suggest that mantle
and basalt composition could differ. Here we measure neodymium isotope ratios in olivine-
hosted melt inclusions from lavas of the Azores mantle plume. We find neodymium isotope …