378 Transactions of the South African Philosophical Society. 



their present outcrops. It is probable that the great accumulations of 

 volcanic rocks, which lie above the ordinary sediments of the Storm- 

 berg Series in the Drakensberg and Basutoland, never extended much 

 further v^est than Molteno, for the volcanic pipes or necks of the type 

 of those of the Drakensberg have not been found west of that 

 neighbourhood. These volcanic rocks have thickened the Stormberg 

 Series in the east, and have also protected the underlying sediments, so 

 that west of the Molteno district the Stormberg Beds have disappeared 

 much more rapidly and completely than east of it. It is quite 

 possible on this view that the Stormberg Beds once extended to the 

 Eoggeveld escarpment, and that v/hen the uplift, which produced the 

 main divide of the Colony, took place, the water which fell upon the 

 newly uplifted land flowed in general north-west and south-east 

 directions over a surface composed of the Stormberg Beds. It is 

 certain that a great thickness of rock must have been removed from 

 the Nieuweveld since the watershed was made. If we are right in 

 our conclusion that the Zwartberg movements took place during the 

 deposition of the Stormberg Series, it follows that the production of 

 the main watershed of the land which resulted from the emergence 

 of those deposits from the water in which they were laid down, 

 was posterior to the production of the great southern anticlines. 



After these anticlines rose from the water, they lost a vast amount 

 of their substance by the ordinary atmospheric agencies. This 

 process went on for long ages before a record was preserved of the 

 events which took place during this great period of denudation in the 

 south of the Colony. This record is contained in the deposits of the 

 Uitenhage Series, the remnants of which are scattered widely between 

 Algoa Bay, or even further east, and the town of Worcester. Near 

 the towns of Worcester and Eobertson the conglomerates of the 

 Uitenhage Series rest directly upon the Malmesbury Beds and also 

 upon the Ecca or possibly higher Beds of the Karroo System, which 

 are faulted down against the pre-Cape rocks, proving that before the 

 conglomerate was formed some 12,000 or 15,000 feet of rock had 

 been removed by denudation on the upthrown side of the Worcester 

 fault." 



The Uitenhage Beds which are of most importance to us in the 

 present connection are the conglomerates, sandstones, and shales, 



* E. H. L. Schwarz, Ann. Rep. of Geol. Comm. for 1896, p. 29. Further accounts 

 of this fault east of Worcester will be found in the Reports for 1897, App. II. and III. ; 

 for 1898, App. III. and V. The estimate of 12,000 feet is obtained by adding up 

 the thicknesses of the Cape System (10,000 feet) and the part of the Karroo System 

 (2,000 feet at least) which have certainly been removed from the area immediately 

 north of the Worcester fault. 



