Naand Crrich amphibole and clinopyroxene are commonly observed in hydrous mantle xenoliths hosted by Pliocene -Quaternary basalts from Yemen. The amphibole is Crrich magnesiokatophorite high in Na 2 O (3.66 -5.65 wt%) and Cr 2 O 3 (2.21 -3.09 wt%), relatively low in K 2 O (0.23 -0.66 wt %) and almost free of Cl and F. The clinopyroxene is characterized by high Cr 2 O 3 (up to 5.64 wt%) and Na 2 O (up to 2.97 wt%), indicating appreciable amounts of kosmochlor. Both minerals show high REE

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... ations as well as HFSE depletion, suggesting an involvement of carbonatitic melt in their formation. The magnesiokatophorites and kosmochlorbearing diopside possibly formed through metasomatism by hydrous Narich carbonatite melt. Magnesiokatophorite is an indicator of metasomatism by hydrous Narich carbonatite in the upper mantle.