Geochemical differences of the Hawaiian shield lavas: implications for melting process in the heterogeneous Hawaiian plume

Numerous geochemical studies have indicated that the Hawaiian mantle plume consists of several distinct components. However, their origin remains controversial, with a number of different interpreta-tions having been proposed. We present new major element, trace element and high-precision Sr^Nd^Pb^He isotope data for a suite of fresh submarine lavas erupted by the Koolau, Kilauea and Loihi volcanoes, which are widely believed to have sampled three distinct Hawaiian plume components.The Sr and Nd isotope compositions of the Loihi lavas are similar to those of Kilauea lavas. However, our double-spike Pb isotopic data show that Loihi lavas have both Kilauea-like and Loihi-like compositions. This discovery implies that the Loihi source region contains a Kilauea-like (‘Kea’) mantle component. Our new data support the existence of three major types of intrinsic plume component: a Loihi component, an ‘enriched’ (Koolau) component and a ‘depleted ’ (Kea) component.We propos