Basalts and trachyphonolites from Huahine Island (Society archipelago) have been analyzed for major elements and several trace elements (including rare earth elements). Eight basalts from the nearby Bora Bora Island were also analyzed for comparison. Ni-MgO, Ni-Ba, and Ni-Rb modeling indicates that the abundances of these elements in Huahine basalts cannot be entirely the result of crystallization and/or accumulation of olivine and reflect a variability already present in a heterogeneous source, a conclusion supported by Pb and Ce data. The chemical variability of Huahine basalts, with respect to several trace elements, can be explained by contamination of the differentiating basaltic melt by a sedimentary reservoir. The same trace element data also suggest that Huahine trachyphonolites can be derived from basaltic magma by assimilation-fractional crystallization or from partial melting of a hawaiite.

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