Carbonatite lavas are unusual because they contain over 50%carbonate minerals and almost no silicate. Volcanic gases captured from Oldoinyo Lengai in northern Tanzania, which is the only currently active volcano to produce such lavas, are shown to be indistinguishable from those emitted along mid-ocean ridges. Oldoinyo Lengai is far removed from oceanic spreading centres, so this suggests that a globally homogeneous reservoir exists in the upper mantle and supplies volatiles to both mid-ocean ridges and continental rifts.
- T. P. Fischer
- P. Burnard
- F. Mangasini
