Erosion and tectonics in the East African Rift System

Abstract

Perhaps I may be allowed to suggest as additions to the list of references appended to Dr. Dixey's paper, J. E. S. Moore's The Tanganyika Problem (London, 1903) and E. Parson's important paper, “The origin of the Great Rift-Valleys as evidenced by the geology of coastal Kenya” (Trans. Geol. Soc. S. Afr. xxxi, 1929, pp. 63-96). The map accompanying my own paper on the “Karroo System in East and Central Africa” ( C.R. Int. Geol. Congr. xv , 1929, S. Aft. ii, 1930, pp. 263-87) gives some idea of what may be termed the paulo-post-Karroo faulting, which, as Dr. Dixey points out, has often been confused ~rith the later “Rift” system. As it was the result of going over much of the area on foot, the paper contains details about various definite points, and attention may be drawn to the fact that both alongside Lake Tanganyika and in the Zambesi Valley all the faulting I saw had the downthrows the wrong way for the depressions to be ascribed to its influence. The fact that the faulting does not completely neutralize the effect of the general dip seems to show that Moore was not so far out, after all, with his “eurycolpic folds”. A point touched upon as long ago as 1903 in the Geological Magazine (1903, p. 548) may be again emphasized here. It is not by any means as certain as seems to be generally assumed that the southern half of Africa has had its present shape for any great length