Sr, Nd and Pb isotope geochemistry of the Oslo rift igneous province, southeast Norway

The mildly depleted mantle proposed as the source for the Oslo rift mafic rocks has an isotopic character which can only be explained in terms of a multistage history which included periods of relatively high U/Pb and Th/Pb ratios, resulting from a relatively short depletion history in the subcontinental lithosphere and metasomatic enrichment of the mantle in selected elements.