Bagzane (Baguezans)

An oval complex of 20x40 km Bagzane forms a plateau some 700 m high. The volcanic nature of the complex is attested by the presence of a vestigial patch of rhyolites in the central part. The complex comprises the relics of three concentric ring-dykes of quartz syenite which have been partly destroyed by invasion of later peralkaline granites and granite porphyries, in which aegirine is the principal mafic mineral. Final activity is represented by alkaline microgranite and biotite granite emplaced along the southern margin of the complex.