THE CRETACEOUS SYSTEM 313 



themselves can usually be distinguished from the Uiten- 

 hage beds by the fact that they cover flat hill tops, 

 often bounded on one or more sides by a low step or 

 krantz, due to the gravels offering more resistance to 

 the weather than the underlying rock, whether the 

 latter belong to the Uitenhage beds or the Bokkeveld 

 or Witteberg series. In the Mossel Bay basin excellent 

 sections showing the unconformity of the gravels and 

 surface quartzites to the Uitenhage beds can be seen 

 in the valley of the Nauga River east of Herbertsdale ; 

 a fine example of a similar unconformity in the Union- 

 dale Division is shown on Plate XXIII. 



West of Swellendam there are two more isolated 

 basins of Uitenhage beds ; one stretches from Eobertson 

 to Ashton, and the other from south of Goudini Road 

 Station to beyond Nuy, passing just south of Worcester. 

 The beds exposed in these basins are red conglomerates, 

 containing pebbles from all the rock series, from the 

 Malmesbury to the Ecca, which crop out within short 

 distances of the Uitenhage beds. The latter rest uncon- 

 formably upon the older rocks south of the Worcester 

 fault, and, apparently, to the north of it also in places. 

 The main part of the faulting certainly took place be- 

 fore the Uitenhage beds were formed, but it is not un- 

 likely that here, as in Uniondale and Uitenhage, there 

 was a recurrence of movement along the old line. The 

 area near Worcester, however, has not been examined 

 with a view to settling this point since the post-Uiten- 

 hage faulting farther east has been clearly recognised. 



The conglomerates are well exposed on the banks of 

 the Kogman's Kloof Biver above Ashton Station, on 



