xxxvi Transactions of the South African Philosophical Society. 



cavities on its adherent surface, into which a corresponding number 

 of processes of the whale's skin project and serve to firmly hold the 

 barnacle. 



Mr. Schwarz, of the Geological Survey, read the following note 

 on the physiography of South Africa : — 



Land surfaces all over the globe are constantly altering their 

 position in regard to their height above sea-level. In some 

 parts of Sweden, for instance, rings used for attaching the cables 

 of ships many centuries ago are now found far inland, while 

 on the west coast of England a contrary movement has taken 

 place, and in many parts forests can be seen under the sea. In 

 Africa the mountains near the sea coast have been formed by 

 the folding of the earth's crust due to the contraction of the 

 globe ; the earth is cooling and the hard rock masses on the 

 exterior are compelled to occupy a smaller space, and therefore 

 crumple up just as a sheet of paper does when it is laid on a smooth 

 surface and the two ends pushed together. The mountain ranges on 

 the inside of the coast belt are probably still in course of formation ; 

 as they rise, the rivers that flow through them have to cut their 

 channel. If there was no movement going on, the rivers would 

 have time to broaden their courses, but in the Langebergen, for 

 instance, at Waaikloof especially, the kloof is so narrow that there 

 is not space for even a footpath alongside the river. There is 

 another cause that is lifting South Africa out of the sea, namely, the 

 loss of attraction on the water due to denudation. In the Karroo 

 one sees isolated hills that were once evidently connected together 

 in one great sheet, but the intervening masses of rock have been 

 removed by the agency of wind and water. On the coast, a similar 

 amount of denudation is apparent in the way the ranges of Table 

 Mountain sandstone are now disconnected. When we come, how- 

 ever, to examine these regions more closely, we arrive at the 

 astonishing result that a far greater denudation has gone on. I 

 was first led to this conclusion by the discovery of beds at Worcester 

 and Eobertson that were once thought to be confined to the Karroo. 

 These Ecca beds were thought to have been formed in a basin of 

 which the Zwartebergen were the southern shores. At Worcester 

 we find the Ecca beds folded in with the Dwyka and Zwarteberg 

 beds in exactly the same way as we find in the Gouph, and beyond 

 doubt these more recent Karroo beds once extended as a sheet over 

 the older beds of the south-west districts. I have roughly estimated 

 the thickness of the beds above the Table Mountain sandstone as 

 follows : Bokkeveld, 2,000 feet ; Zwarteberg, 2,000 feet ; Dwyka, 

 500 feet ; Ecca (at Worcester), 500 feet ; giving a total of 5,000 feet. 



