THE CAPE SYSTEM 135 



Mountain series are lamellibranch shells, not well- 

 enough preserved for determination, which occur in 

 thin-bedded and micaceous sandy shales at the very 

 base of the series on the pipe track to the Slangoolie 

 ravine above Camp's Bay. 



The question of the conditions under which the Table 

 Mountain series was deposited has not yet been satis- 

 factorily solved. The rocks are, with the exception of 

 the shale bands, essentially coarse-grained deposits, yet 

 this character is maintained over very wide areas ; 

 from the Peninsula to Algoa Bay, nearly 430 miles in a 

 straight line, and from Cape Point to the north end of 

 the Bokkeveld Mountain, a distance of over 225 miles, 

 the same coarse sandstone with isolated quartz pebbles 

 is met with ; in Pondoland again, 290 miles from Algoa 

 Bay, the sandstone is of identical character with that 

 of the western area, and maintains its character at 

 least as far as the Natal border. North of Agulhas 

 the Table Mountain sandstone is seen at intervals for 

 about 100 miles. It is clear, then, that the coarse 

 sandstones that make up the bulk of the series were 

 deposited over an area of at least 43,000 square miles, 

 probably over more than 90,000 square miles, and even 

 then the Pondoland outcrops have been left out of ac- 

 count owing to the uncertainty of the nature of the 

 rock between them and Algoa Bay. 



During the denudation of the land that furnished this 

 great bulk of sand, mostly quartz sand, an equal or 

 greater amount of finer-grained material, muddy matter, 

 must have been produced, but of these fine-grained sedi- 

 ments the only traces in Cape Colony are the shale 



