Badda is a large volcano lying immediately east of, and overlapping, Chilallo (No. 42). Like Chilallo it appears to be formed predominantly of alkaline trachyte lava flows. Extending southwards from Badda for some 70 km is the Sagatu Ridge which is the dissected remant of a 7 km wide fissure system (Mohr, 1980), the central 2 km of which is the locus of a dyke swarm. In the Badda sector of the swarm, in particular, the dykes are markedly bimodal comprising hawaiite and comendite. The comendites contain anorthoclase phenocrysts up to 1 cm long in a matrix of minute laths of alkali feldspar and accessory aegirine-augite and aegirine, which sometimes form microphenocrysts, riebeckite, aenigmatite, quartz and magnetite. Analyses of 25 rocks, including some trace element data, are given by Mohr (1980), and Sr isotope data are in Kennan et al. (1990).