14 THE FOLDED BELT 



the ocean side of the belt they are found. The intrusions 

 are either nearly horizontal sheets, or steeply inclined 

 dykes. The sheets are confined to the inland side of the 

 folded belt, and also, almost entirely, to the Karroo beds. 

 Individual sheets may extend over or through thousands 

 of square miles. The dolerite outcrops cease abruptly 

 along a line drawn from the Tanqua Karroo eastwards 

 through Beaufort West, and the abrupt escarpment of 

 the Koggeveld and Nieuweveld, along which the surface 

 of the country drops some 3,000 feet to the Great Karroo 

 and the Gouph, is evidently due to the protection afforded 

 by thick sheets of dolerite to the weaker sedimentary 

 rocks and, to a less extent, to the hardening of the latter 

 along the contacts. 



Travelling southwards through the Great Karroo one 

 passes almost insensibly from very gently inclined 

 strata to the steeply dipping beds in front of the southern 

 mountain ranges. Though the transition is generally 

 gradual there are places where there is a rapid increase 

 in dip, but these localities are south of the belt of 

 country where the inclination becomes conspicuous. 



The folded belt runs in a southerly direction from the 

 neighbourhood of Van Rhyn's Dorp to Cape Hangklip, 

 but from Ceres southwards it also turns eastwards and 

 is continued till it is cut off by the coast near the mouth 

 of the Gualana River. 



This area is chiefly composed of the three members 

 of the Cape system, the lowest of which, the Table 

 Mountain series, forms the mountain ranges of the 

 Cederbergen, Drakensteins, Langebergen and Zwarte- 

 bergen, to mention only some of the more important 



