50 THE IBIQUAS SERIES 



some distance from the foot of the escarpment, and the 

 highest beds visible lie about fifteen miles to the east, 

 where they are covered by the Dwyka conglomerate. 

 Although the beds are partly repeated by folding be- 

 tween the western and eastern boundaries, their whole 

 thickness must be several thousands of feet. 



The northern limit of the beds is a fault, along which 

 they have been let down against the granite and gneiss 

 of Bushmanland. The fault is seen on Ezel Kop Vlakte 

 and Klomp Boomen, two farms west and south-west of 

 JLoeries Fontein, but its western course has not been 

 traced. The throw of this fault is not known. As the 

 Ibiquas beds nowhere show any signs of contact meta- 

 morphism due to the proximity of the granite under- 

 ground, and as they contain large quantities of material 

 derived from a granitic region probably not far away 

 from the neighbourhood, the Bushmanland granite may 

 be safely regarded as the older rock. The foliation 

 planes in the gneiss of the Langebergen and the south 

 end of Bushmanland have a nearly east and west strike, 

 and would seem to belong to a much older period than 

 the movements which gave the Ibiquas beds their pre- 

 valent north and south folds. 



The only intrusive rocks hitherto found in the Ibiquas 

 beds are dykes of dolerite, evidently belonging to the 

 same group of intrusions that form the sheets and dykes 

 in the country occupied by the Karroo formation to the 

 east and south-east. 



The section in Fig. 6 illustrates the structure of the 

 Ibiquas beds in the Doom Kiver Valley. The line of 

 section is so chosen that it runs across the fault on 



