﻿198 MESSES. A. R. ANDKEW AND T. E. G. BAILEY [May I9IO, 



Approximate thickness 

 in feet. 

 Top not seen. 



1 . Strongly-bedded, often schistose flags 1300 



2. White quartzites with ' honeycomb weathering ', and 



felspathic sandstones 470 



3. Brown and grey, sometimes schistose flags, with occa- 



sional bands of conglomerate consisting of white 

 quartz-pebbles in a siliceous and micaceous matrix, 

 and with 10 feet of dark carbonaceous phyllite at 

 the base 2470 



4. Hard, compact, very thickly-bedded quartzites 600 



5. Hard and soft, white or pinkish, felspathic sandstones 



and grits, with some flags and quartzites 4050 



6. Brown and grey, -very felspathic sandstones, with few 



flags 220 



7. Soft white flags and sandstones 680 



Base not seen. 



Total seen 9790 



The structure of the area is simple, except in the northern 

 ■extremity, where complications arise. The general strike is 

 roughly north-east and south-west, and the dip varies from 40° to 

 75° towards the north-west. In places, however, the beds may 

 become vertical, and in one case are overturned. In the north the 

 strike changes to an easterly and westerly direction and the beds 

 dip at times from 50° to 80° southwards. Near Namitawa Moun- 

 tain the beds are folded into a small syncline, with comparatively 

 low dips. The northern junction with the gneiss is probably a 

 faulted one. No fossils have been discovered in the Mating! Beds, 

 and so their age is uncertain ; but, from the general character of the 

 rocks, it is safe to assume that they are earlier than the Karroo 

 System. In German East Africa Dr. Bornhardt has described what 

 appear to be a similar series of quartzites, grits, and sandstones, and 

 has compared them with the Cape Beds of South Africa. Quartzite 

 formations are also known in the Transvaal. 



(2) The Karroo Series. — The ancient quartzite formations of 

 the Transvaal are succeeded by a thick series of sandstones, con- 

 glomerates, shales, and volcanic rocks, which lie with considerable 

 unconformity upon the older rocks beneath. This system is known 

 as the Waterberg, and is in turn overlain unconformably by the 

 Karroo. The question arises as to how far the Waterberg Series may 

 have extended northwards. While there is a temptation to include 

 some of the older sandstones and shales of the Congo-Tanganyika 

 area with the Waterberg Series of the Transvaal, the fossil evidence 

 appears to be conclusive that the sandstones of the Nyasa region 

 belong exclusively to the Karroo, with the exception of limited 

 exposures on the north-western border of the lake, which are of 

 recent age. Karroo beds occur in the north of Nyasaiand, and 

 along the south-western border. The two occurrences are separated 

 by a wide expanse of crystalline rocks. The Karroo of Northern 

 Nyasaland forms isolated patches of comparatively low ground, 



