Mantle noble gas abundance ratios inferred from oceanic basalts and model estimates

We investigated mantle noble gas abundance ratios using a global compilation of data from mid-ocean ridge basalts (MORB) and high 3He/4He ocean island (OIB), coupled with calculated abundances based on closed-system evolution models. Assuming that the sources MORB OIB are derived same early Earth parental material, variations in their useful to ascertain which source is more depleted or degassed, if gases might be hybrid different materials. Therefore, compositions can key elucidating structure. patterns Monte Carlo approach validated end-members, provides new estimates for uncertainties. The adequacy values was confirmed by existing data. compiled all published extracted total heating glassy oceanic basalts, enables estimation pristine including Kr both OIB. estimated correcting measured atmospheric influences elemental fractionation. corrected resemble proposed end-members relative similar those C1 chondrites range He Kr, supporting hypothesis less degassed primitive exist Earth's mantle. By contrast, shows depletion lighter gases, but helium content compared source. contrast He/Ne between OIB, constraint models, andis expected reflect several stages diffusive fractionation during history, initial sources, would require heterogeneous accretion.