Analysis of helium isotope ratios in volcanic hotspot lavas suggests that hotter, more buoyant plumes upwelling from the deep mantle entrain high-3He/4He material, unlike cooler, less buoyant plumes, implying the existence of a dense, relatively undisturbed primordial reservoir in the deep mantle.
- M. G. Jackson
- J. G. Konter
- T.W. Becker