TERTIARY AND RECENT DEPOSITS 407 



400 feet above high tide in its inland portion to 200 feet 

 where it is concealed under the blown sand of the coast. 

 The shelf is covered in places with shelly conglomer- 

 ates containing glauconite and the remains of mollusca 

 still living off the South African coast. A characteristic 

 shell in this deposit is a very large Pectunculus. At 

 lower levels nearer the sea there are patches of old 

 beaches which contain shells belonging to living species. 1 

 Many of these raised beaches contain numerous species 

 of shells, and the careful collection and determination 

 of these from the different deposits is certain to yield 

 interesting results. 



Although the evidence bearing on the question of a 

 recent change in level of the whole coast line is so 

 widely distributed much remains to be done before it 

 can be fully understood. So far as it goes, it is in ac- 

 cordance with the presence of the river-cut high-level 

 plains now deeply channelled by the existing streams. 

 There is good reason to believe that while these plains 

 were being made the higher raised beaches were also in 

 process of formation. In the Swellendam Euggens, for 

 instance, the old gravel and alluvial plateau that slopes 

 gradually towards the coast and is trenched by tribu- 

 taries of the Breede Kiver terminates at the foot of the 

 Bredasdorp limestone hills, which we have seen were 

 once calcareous sand dunes. These are continued into 



1 Descriptions of the occurrences will be found in Stow, Q. J. G. S. t 

 xxvii., p. 497 ; Johnson, T. G. S. S. A., vi., p. 9 ; Schwarz, T. G. S. S. A., 

 xi. A list of shells from a low-level raised beach near Mossel Bay is in 

 G. C., x., p. 293. Prof. Schwarz includes the beach deposits of Uitenhage 

 and Alexandria with the Need's Camp beds (Danian) of East London in 

 one group under the name of Alexandria formation.. 



