422 Transactions of the South African Philosophical Society. 



proves a safe foothold in climbing. It is usually cream or white, 

 sometimes light red in colour, and being compact and fairly uniform 

 in texture, it either breaks away in huge masses, leaving cliffs with 

 very straight walls, or it projects beyond the softer beds below. An 

 overhang of 20 ft. is very common, the mass being occasionallv 

 from 100 ft. to 150 ft. and in a few cases even over 200 ft. thick, with 

 no signs of breaking away. In the Bushman's River district the 

 overhang is often greater than 30 ft., and in one place it is over 

 60 ft., but there the lower portions have fallen in, leaving a com- 

 paratively thin roof. 



This upper series of sandstone is a good geological landmark along 

 the whole sixty miles from Giant's Castle to Mont aux Sources, 

 while the cliffs formed of it are the most striking feature in the 

 scenery of the spurs. It varies in thickness from 200 ft. to 600 ft., 

 the top of it always being from 5,900 ft. to 6,100 ft. above sea-level. 

 As far as I could judge from scores of sections, it is quite horizontal. 

 At Tabaimhlope the sandstone must be over 800 ft. thick at the 

 south end. I found no fossils, but noticed a few round, hard sand- 

 stone nodules, often containing a little pyrites such as one finds in 

 the sandstones used for building in the Free State. The huge 

 masses of sandstone that have broken off and lie scattered over the 

 mountain slopes add much to the effectiveness of the valley scenery 

 among the spurs. 



Below the thick mass of sandstone are two beds with marked 

 characteristics, forming the walls of the so-called caves. The upper 

 is rather a friable, light-coloured, marly sandstone, which weathers 

 so that it frequently looks like a row of barrels on end, or a series 

 of stunted columns. It is not a thick bed, being seldom more than 

 6 to 10 ft. I found it associated with the cave sandstone in the 

 Free State as well as at the various caves of the Bushman's River 

 system, but it was not developed in quite so marked a way as at 

 Tugela. It rests on a bed of nodular sandstone from 5 to 15 ft. 

 thick, varying in different localities. This rock I found at Pilani, 

 in the Orange Free State, in the same relative position. Below is 

 a deep, pink, earthy layer 2 or 3 ft. thick. Where exposed, eland 

 and cattle tracks lead to it from several directions ; the animals go 

 to lick the rock. 



Below this comes another layer of sandstone similar to that of the 

 cliffs above but not so thick ; it forms cliffs and escarpments of less 

 importance. 



The remainder of the slopes down to the bottom of the valley is 

 much covered with vegetation ; but there are numerous sandstone 



