Fossil Plants from Tanganyika. 387 



sandy clays, probably never exceeding 100 feet in thickness, and 

 generally much less. 



" In general this area may be described as a slightly uplifted pene- 

 plain with a gentle slope eastwards from about 800 feet above sea- 

 level along its western margin to about 200-150 feet at a distance of 

 two to five miles from the sea, where it drops fairly steeply to the 

 relatively narrow coastal platform of coral rock and tidal mangrove 

 swamps and estuaries. 



" The sediments under consideration fall roughly into three divisions, 

 a lower, middle, and upper group. In the lower division 

 conglomerates, arkose and felspathic sandstones predominate, but 

 numerous bands of dark carbonaceous shale are interbedded. These 

 beds probably correspond with, the Tarn Grits ^ of Kenya Colony. 

 No identifiable fossils have been obtained from them in this territory, 

 but comminuted plant remains are abundant in the* interbedded 

 dark shales. 



" The middle division appears to follow conformably and is 

 distinguished by a considerable thickness of strata in which dark 

 carbonaceous shales and flagstones prevail. They contain abundant 

 plant remains, unfortunately poorly preserved, but nevertheless 

 yieldiiig the best fossils of the region. These beds may correspond 

 with the Maji-ya-Chumvi beds ^ of Kenya, though the shales have 

 not yet provided any very satisfactory fossils comparable with those 

 of Tanganyika territory. 



" The upper division follows without any break and consists of 

 irregularly bedded sandstones alternating with lighter coloured 

 somewhat sandy shales. Sandstones tend to predominate in this 

 section and show considerable range in texture and appearance. 

 One characteristic type occurs near V^ijinga, just above the junction 

 of the Ndoyo and the Kombe : it is fine-grained and minutely false- 

 bedded and weathers to a peculiar almost woody structure. Another 

 type, that of Kirimba and Kilulu hills is very coarse grained and 

 poorly cemented. The shales contain occasional though frag- 

 mentary plant remains. This group probably includes representa- 

 tives of the remaining upper portion of the Duruma Sandstone 

 of Kenya,^ such as the Mariakani and Mazeras Sandstones and the 

 Shimba Grit. 



" The whole series has a uniform dip seawards at a low angle ranging 

 from 5 to 10 degrees. Local small undulations occur but do not 

 disturb the general structure and succession. A pronounced and 

 persistent zone of minute puckering in certain of the shale bands of 

 the middle division was traced at intervals along the strike through- 

 out the region. The only evidence of faulting noted was along the 



^ H. B. Maufe, Report relating to the Geology of the East African Pro- 

 tectorate, Col. Reji., Misc. No. 45 (Cd. 3228), London. 



2 H. B. Maufe, op. cit. ; and J. W. Gregory, The Eift Valleys and Geology 

 of East Africa, 1921, p. 52. 



^ H. B. Maufe, op. cit. 



