432 Transactions of the South African Philosophical Society. 



enormous numbers of minute fragments of shells, made of carbonate 

 of lime. When rain-water falls on the sand it sinks in and dissolves 

 some of this carbonate of lime. The saturated sand then loses its 

 water partly by evaporation at the surface, partly owing to the water 

 sinking through it and running off at the first opportunity. The 

 water lost by evaporation at the surface will leave behind any 

 dissolved carbonate of lime that it has taken up during its stay in 

 the sand as a deposit round the grains near the surface. This, no 

 doubt, accounts for the rapid hardening of calcareous sands where 

 exposed to the weather. It is probable that a slow process 

 of solution and redeposition of carbonate of lime goes on continually 

 throughout the deeper-seated parts of calcareous sand-dunes. 



The present position of the Bredasdorp and other limestone ranges, 

 which are at a considerable height above sea-level, must be due to 

 a change in level since their formation. The ground between the 

 hills and the shore is remarkably flat, when the modern sand-dunes 

 are left out of consideration. The absence of definite ridges of 

 moving sands at such a distance from the shore at the present time, 

 makes it difficult to understand what could have caused them in 

 former times. If, however, we take the limestone ranges to be of 

 the same nature as the modern lines of dunes along the coast, the 

 difficulty vanishes. 



There is, however, other evidence of a change in level along the 

 south coast within recent times. 



The rock shelf, which is found conspicuously developed between 

 Mudge Point and Zout Anysberg, is extremely difficult to explain 

 otherwise than as a raised beach. The shelf is cut for the most part 

 in hard quartzite, and the contrast between the flat ground near the 

 shore, with the numerous smooth outcrops of quartzite, and the 

 rugged surfaces which the same rock shows in the hills rising 

 abruptly on the landward edge of the terrace is very striking. 



Near Uilenkraal Eivqr, and also near Zout Anysberg, the limestone 

 hills lie at the back of such terraces, and outlying patches of the 

 rock are found perched high up on the adjacent hills of Table 

 Mountain sandstone, in such positions that could hardly be reached 

 by sand-dunes under present conditions. 



Near Cape Infanta the cliffs are formed of Table Mountain sand- 

 stone on the lower half and of limestone on the upper ; near the 

 base of the latter, or about 100 ft. above sea-level, there is a bed of 

 large pebbles, while a similar, or perhaps the same bed, is seen on 

 the surface of the ground near the head of a ravine which cuts right 

 through the limestone in the same neighbourhood (fig. 2). This 



