Abstract
Abundances of U have been determined in minerals of the spinel peridotite xenoliths in basaltic rocks from Hoggar (Southern Algeria) by the fission-track method. Olivine and spinel have the lowest U abundances (∼ 0.10–0.13 ppm) followed by orthopyroxene (∼ 0.22–0.24 ppm). The clinopyroxene has a large variation of U (0.23–0.74 ppm). The contents of U in amphibole are within the range of those of clinopyroxene (∼ 0.30–0.37 ppm). Although most of the U in the xenoliths is homogeneously distributed in the major rock-forming minerals, the whole-rock U abundances are at least twice as high as estimates of the upper mantle. The high contents of U even in rocks without amphibole is probably due to metasomatism by a fractionated fluid phase which took place before or during the recrystallization. The host basaltic rocks are not genetically related to the spinel peridotite.
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Dostal, J., Dupuy, C., Dautria, J.M. et al. Uranium in peridotite inclusions in basalts from Hoggar (Southern Algeria). Bull Volcanol 47, 627–634 (1984). https://doi.org/10.1007/BF01961231
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DOI: https://doi.org/10.1007/BF01961231