Evidence for a deep mantle source for EM and HIMU domains from integrated geochemical and geophysical constraints

We show that hotspots associated with seismically defined plumes show a greater likelihood of hosting lavas with either extreme EM (143Nd/144Nd ≤ 0.512630) or extreme HIMU (206Pb/204Pb ≥ 20.0) compositions than hotspots not associated with plumes, but HIMU hotspots show a stronger association with plumes than EM hotspots. The significance of the relationship between plumes and extreme geochemical signatures at hotspots improves if extreme EM and HIMU compositions are considered together instead of separately: hotspots sourced by mantle plumes are even more likely to exhibit extreme EM or extreme HIMU signatures than hotspots not sourced by plumes. The significance tests also show that hotspots with extreme EM or HIMU compositions are more likely to be associated with mantle plumes than hotspots that lack extreme geochemical signatures. A relationship between seismically detected deep mantle plumes and the presence of extreme EM or HIMU compositions at hotspots provides evidence for a deep mantle source for these geochemical domains.