8 THE PLATEAU REGION 



it runs northwards round the north end of the Ceder- 

 berg folds and turns south through the Tanqua Karroo ; 

 in the country beyond Karroo Poort it takes an easterly 

 course to the shores of the Indian Ocean between the 

 Gualana River and East London. 



The first of these two regions is essentially a country 

 of plateaux, and though it also forms the low-lying 

 coast belt in the west of the Colony it can be conven- 

 iently called the Plateau Kegion ; the second or Folded 

 Belt is characterised by folds which have played a very 

 important part in determining its existing surface fea- 

 tures. 



The plateau region is itself sharply divided into two 

 parts by the presence or absence of the Karroo forma- 

 tion above the very ancient rocks which predominate 

 at the surface in its north-western and northern parts. 

 As yet very little is known of the north-western corner 

 of this region ; the accounts given by Wyley and Dunn 

 show that it is largely made of granite and gneiss in- 

 trusive in schistose rocks of various kinds, and that 

 there are considerable areas of horizontal quartzites 

 lying on the schists and gneiss. Various opinions have 

 been expressed as to the relationship of these quartzites, 

 but until some one familiar with the several unfossilif- 

 erous quartzitic formations in other parts of the Colony 

 has examined them, their significance must remain un- 

 certain. 1 The southern end of the north-western granite 



1 From descriptions in a note-book of the late Dr. Atherstone, Prof. 

 Schwarz infers that the quartzites belong to the same group as the 

 Nieuwerust beds of Van Rhyn's Dorp (G. M., 1908, p. 425). 



