

THE CAPE SYSTEM 147 



fossils other than badly preserved plant remains. These 

 are not so well defined as the lower groups, and both 

 the shales and sandstones are often very micaceous. 

 The fourth shale group is taken as the uppermost of 

 the Bokkeveld series, and the beds in it often closely 

 resemble those belonging to the Witteberg. The di- 

 vision between these two series is an arbitrary one, and 

 cannot be laid down with certainty in the absence of a 

 clearly exposed succession from below. In the country 

 north of the Zwartebergen, in the Cold Bokkeveld, and 

 in the Hex Eiver-Ladismith Karroo district, there is 

 not much difficulty in fixing upon a boundary which 

 is probably at one and the same horizon throughout ; 

 but south of the Langebergen the task is an impossible 

 one, and the limits of the Witteberg beds there as laid 

 down upon the map must be considered as only roughly 

 correct. 



Along the northern slope of the Langebergen the 

 Bokkeveld beds are very much cleaved ; the cleavage 

 planes have a constant and high inclination to the 

 south, while the dip of the beds is very variable in 

 amount, and in direction is either nearly north or south, 

 the strike of the beds being nearly east and west, par- 

 allel to the cleavage. There is usually no difficulty in 

 distinguishing between the bedding planes and cleavage 

 in this district, for the sandy portions of the rock resist 

 the weather better than the finer grained beds, and 

 stand out more or less prominently on the hill-sides. 

 South of the Langebergen, however, especially east and 

 south of the Eobertson Division, the distinction between 



the two sets of divisional planes is much less marked, 



10* 



