462 GEOLOGY OF CAPE COLONY 



The Uitenhage series furnishes good freestone at 

 Oudtshoorn. 



The dolomitic limestone of the Campbell Eand series 

 makes an excellent building material, as it occurs in 

 very uniform layers and is easily worked ; both it and 

 the Black Eeef beds are much used locally in the north. 



The granite of the Peninsula is much used for founda- 

 tions and for coping, but is often disfigured by dark 

 patches. A fine example of this stone is to be seen in 

 the Ehodes Memorial above Groot Schuur. The granite 

 of the Paarl and Kraaifontein is finer grained and not 

 so coarsely porphyritic. 



The dolerite of the Karroo is very durable, but it is 

 hard to work, while its dark colour is unpleasing to the 

 eye. It is an excellent stone for road metal, and much 

 preferable to the granite or impure quartzite generally 

 used in the Peninsula. 



At Hoetjes Bay, an inlet of Saldanha Bay, a recent 

 limestone has been extensively quarried. A piece of 

 this limestone contained a smaller proportion of quartz 

 sand than usual in such rocks, about 12 per cent., but the 

 composition may vary considerably. When newly quar- 

 ried it is soft and can be easily worked, but it hardens on 

 exposure. From the appearance of the surface in such 

 buildings as the General Post Office and the South 

 African Museum in Cape Town, the Saldanha Bay stone 

 does not appear to be a durable one in the Cape climate. 



Clays. Clays suited for the manufacture of tiles or 

 pottery- ware are rather poorly represented in the Colony. 

 In a few localities in the Western Province slates of 



