Ancient helium and tungsten isotopic signatures preserved in mantle domains least modified by crustal recycling

The goal of this study is to characterize a suite of mid-Miocene Icelandic lavas that exhibit extremely high 3He/4He (up to 43 Ra, ratio to atmosphere). Whole rock radiogenic isotopes (i.e., long-lived radiogenic isotopes of Sr, Nd, Pb and Hf) were measured, as were whole rock major and trace element concentrations. 182W isotopic compositions were reported for one high 3He/4He Icelandic lava, and an anomalous composition is reported. The new geochemical dataset is placed in the context of geochemically characterized ocean island basalt lavas for which 182W has been measured. The study reports that lavas with high 3He/4He and anomalous 182W are found in ocean island basalts with the weakest signatures associated with crustal recycling.