Geochemistry and U-Pb zircon dating of the high-K calc-alkaline basaltic andesitic lavas from the Buanji Group, south-western Tanzania

The geochemical features of the Buanji Group high-K calc-alkaline basaltic andesites are interpreted in terms of derivation of these rocks by partial melting of the a spinel lherzolite mantle wedge that has been metasomatized by the subduction related fluids in a late Paleoproterozoic continental convergent margin. The resultant magmas were subsequently contaminated by the felsic crust prior to their emplacement.