INTRODUCTION 



17 



There is some evidence in favour of the view that the 

 Cederberg system of folds began to be formed rather 

 earlier than the Zwartberg, but 

 probably each reached its great- 

 est development at about the 

 same period, at some time be- 

 tween the deposition of the 

 Ecca and that of the Uitenhage 

 series. 



The folding is most intense 

 in the east and west trending 

 portion of the rocks involved. 

 Northwards from the country 

 between Tulbagh and Karroo 

 Poort the anticlines or arches, 

 into which the rocks have been 

 bent, are less sharp and less 

 numerous than to the east of 

 the same neighbourhood. The 

 anticlines of the Cederberg sys- 

 tem gradually flatten out north- 

 wards, so that on the latitude 

 of Van Ehyn's Dorp village 

 hardly a trace of the folds is to 

 be met with in the rocks which 

 are so greatly disturbed farther 

 south (see Fig. 2). At the same 

 time the rocks belonging to the 

 Cape formation gradually thin 

 out in such a way that the base of the Karroo forma- 

 tion, the Dwyka series, is found to lie upon lower and 



