CHARACTERISTICS OF SOME TANGANYIKA SOILS

Abstract

Summary A series of soils from two areas of Tanganyika have been studied mineralogically. They are derived in the main from amphibolite, but only a small proportion of the more resistant ahminosilicate minerals survive in the soil. The clays (<1.4μ) of the red loams are characterized by a predominance of kaolinite, whereas the more poorly drained grey soils have a disordered kaolin. Other components of the clays are iron oxides and small amounts of illite. The pallid soils contain moderate amounts of montmorillonite in the weathering zone, some of which persists into the soil. The mbuga and black valley soils contain montmorillonite or iliite, with subordinate kaolin.