THE L-AL"LT SVSTJ':.\1S IX SofTLi OF SOUTH AFRICA. ,^75 



Bokkeveld, the valley in which the village of Ceres lies, there is 

 a great stretch of yellow quartzites of the Witteberg Series. It 

 is in these Witteberg Mountains that the monoclines are seen to 

 the best advantage. North of the village of Ceres there is the 

 great wall of tlie escarpment of the Waagenboom's Mountain, 

 consisting of a cliff showing the layers of the Witteberg beds; 

 on top there is a plateau of the topmost of the Cjuartzite layers, 

 dipping northwards at an angle of some 15°. If these layers 

 continued to dip northwards at this angle the overlying Dwyka 

 would soon be found covering them, but before this can happen 

 there is an abrupt monocline bringing up a strip of Witteljerg 

 rocks to the same level as the far end of the first block. 1liis 

 second dips at the same angle, and in turn is brought up against 

 a monocline. Some 30 or 40 of these monoclines can be found 

 in this area, all extending parallel to each other in an E.S.E. 

 direction ; once only, to the north of Ceres village, the Dwyka 

 beds are brought down to the level of the surface of the country, 

 and at the northern end of the inclined block, instead of the usual 

 monocline, there is a fault. Of course, the Dwyka conglomerate 

 at one time covered all this area, but owing to its more argilla- 

 ceous character, it has yielded more readily to the action of 

 denudation, and all traces of it have been removed from the 

 elevated portions of these mountains ; the Witteberg quartzites, 

 therefore, which are very hard near the top, and resist weather- 

 ing, are. as it were, cleaned of their covering, and show in naked 

 outline this remarkable system of monoclines. Between the dip- 

 slopes and the monoclines there are naturally valleys which, in 

 this area, have also had the overlying Dwyka beds cleaned oft' 

 them by denudation, so that we find here the rare case of rivers 

 running in valleys formed for them l:)y the folding of the rocks. 

 In the area north of Ceres (and the same is seen round Con- 

 stable, on the main line from the Cape to the North), the larger 

 rivers cut right through ever}thing irrespective of the hardness 

 of the rock or the presence of folds, but the smaller tributaries, 

 having less erosive power, lie in these structural valleys, and 

 mav be seen in a large scale-map all running in parallel courses 

 and at nearly equal distances apart. 



The faults belonging to the system under discussion run 

 more or less parallel to the folds. The folds are arranged in 

 two great lines east and west, north and south ; the angle where 

 they meet is a schaarung or knot lying actually in and around 

 the Warm Bokkeveld ; from here the trend lines of the folds 

 stream out in a south-westerly direction towards Cape- Town. 

 Had the two systems of folds been of equal value, the resulting 

 angle-folds should have formed in a direction exactly bisecting 

 the angle at which the two systems met — that is to say, witli the 

 two main folds running east and west and north and south, 

 the folds starting from the angle ought to run exactly south- 

 vest. In our case of the Western Province, however, the east 

 and west lines of mountains, including the Zonder Einde. Lange- 



