Published online by Cambridge University Press: 01 May 2009
Annular mounds of clinkery lava encircling shallow depressions floored with similar lava were recently discovered by the late A. D. Combe in S.W. Uganda. From their morphological, petrographic, and chemical peculiarities, here described, it is inferred that they represent transfusion products of superficial tuff occupying the sites of unusually hot fumaroles. The dominant added materials are found to be iron oxides, TiO2, K2O, and P2O5. It is suggested that the P2O5, which is abnormally abundant, may have been derived from bone beds in the underlying Kaiso Series.