2*0' 



448 Annals of tin; South African Museum. 



up of an alternating series of sandstones, which get finer-grained 

 towards the top, and purple mudstones. The sandstones are white 

 and the two uppermost bands contain flattened pellets of pale blue- 

 green shale. 



The junction between the Upper Beaufort Beds and Red Beds appears 

 to be an unconformable one, but is without angular discordance. 



CAVE SANDSTONE. 



h'/liotf. The Cave Sandstone here is a massive yellowish fine-grained 

 felspathic sandstone of remarkable uniformity of texture. It is slightly 

 stratified at its base, and sometimes more so at its summit: but 

 lamination is usnallv absent. Some sections show false-beddinc; on 



/Beds 



Af/sA 



__Wluttsh gritty fi.S. 



lifiji 



er 



Fig. 52. Bezuidenhout's Pass, O.F.S. border. 



an extensive scale. When fresh, the rock is pinkish or reddish in tinge. 

 Its maximum thickness, as displayed at the Barkly Pass, is 800 feet. 

 Occasionally the sandstone is replaced over short distances by thin 

 yellow sandstones and purple mudstones; similarly in Matatiele it is 

 replaced locally by red clay, often mottled with green or alternating 

 with light blue clay. At the top, the rock is sometimes interbedded 

 with lavas and ash. 



Barkly East, W^dehouse, AH teal and Hersclid. In these districts the 

 rock is a fine-grained sandstone, usually pale yellow in colour, but 

 varied by white, buff, pink, and blue. It is generally unbedded, but 

 in places its upper portion is laminated. False-bedding is not un- 

 common, and is sometimes extensive. 



In places the sandstone is split up by layers of ash and lasaltic 

 lava. The thickness is very variable, ranging from 150 feet to 800 ft, 

 I u Toit, in his Report on these Divisions, compares the Cave Sand- 



