A deep mantle source for high3He/4He ocean island basalts (OIB) inferred from Pacific near-ridge seamount lavas

Major element chemistry of ocean island basalts — Conditions of mantle melting and heterogeneity of mantle source

Major element variations in Hawaiian shield lavas: Source features and perspectives from global ocean island basalt (OIB) systematics

[1] Among volcanic hot spots globally, Hawaii has the highest magma flux, yet there is significant controversy surrounding the composition of the mantle sourcing Hawaiian lavas. In order to place constraints on the source lithologies of Hawaiian lavas, we explore relationships between major elements and radiogenic isotopes in tholeiitic, shield-building lavas. Olivine-fractionation corrected la...

Volatiles in Basaltic Glasses from Loihi Seamount, Hawaii: Evidence for a Relatively Dry Plume Component

New H2O, CO2 and S concentration data for basaltic glasses from ‘hotspot’, with temperature differences of 200°C or more between hotter upwelling plumes and the ambient mantle Loihi seamount, Hawaii, allow us to model degassing, assimilation, adiabat (e.g. White & McKenzie, 1989; Campbell, 1998; and the distribution of major volatiles within and around the Davies, 1998). In contrast, it has lon...

Episodic entrainment of deep primordial mantle material into ocean island basalts.

Chemical differences between mid-ocean ridge basalts (MORBs) and ocean island basalts (OIBs) provide critical evidence that the Earth's mantle is compositionally heterogeneous. MORBs generally exhibit a relatively low and narrow range of (3)He/(4)He ratios on a global scale, whereas OIBs display larger variability in both time and space. The primordial origin of (3)He in OIBs has motivated hypo...

Beyond EM-1: Lavas from Afanasy-Nikitin Rise and the Crozet Archipelago, Indian Ocean

Lavas from Afanasy-Nikitin Rise, possibly the Late Cretaceous product of the Crozet hotspot, cover a wide range of isotopic compositions that includes the lowest (Pb/Pb)t (to 16.77) and «Nd(t) (to 28) values yet found among oceanic islands or spreading centers worldwide, as well as high (Sr/Sr)t (to 0.7066). In contrast, young basalts from the Crozet Archipelago exhibit a narrow range of variat...