Cerium isotope geochemistry of ocean island basalts.
Abstract
138Ce/136Ce ratios are reported for eight samples of ocean island basalts (from W. Molokai, Kiluaea, St Helena, Azores, Samoa, Kerguelen and Tristan da Cunha). When these ratios are plotted against published Nd isotope data, they form a 'mantle array' of compositions which indicates coherent behaviour of the two elements during mantle differentiation. This precludes the recycling into the deep mantle of ocean-floor sediments with a large net Ce anomaly.-R.K.H.