A SOIL CATENA ON GRANITE IN SOUTHERN RHODESIA

Summary A catena on the Mid-Tertiary surface near Salisbury, Southern Rhodesia, has developed over granite. Both land form and rock form indicate a two-cycle landscape. The climate is sub-tropical with a 33-in. rainfall and the vegetation is a variant of Braclzystegia savannah woodland. Profiles of good and imperfect drainage have three main horizons, namely, M (mineral); over, F/S (ferricrete and stones); over, W (weathered rock) horizons. Poorly drained soils exhibit G (gley) horizons. The W horizon of a hill-top soil comprises material at an early weathering stage below 12 ft having a platy structure, well-developed clayskins, and fresh minerals, but older material above that depth does not correspond to Van Wambeke's criteria for ante-Pleistocene materials. Dynamic soil-forming processes include lateral movement of the M horizon by sheetwash and truncation of the W horizon by insect activity.