STOW SOITTH-AFKICAN GEOLOGY. 539 



been subjected to oceanic agency: we must therefore look for other 

 causes to account for the vast alteration that the surface of the 

 country has undergone. 



Some of the facts that I have been able to coUect as beariug upon 

 the case are as follows : — 



Katherg, and its Roches moutonnees and Moraines. — Commencing 

 with the Katberg range, we remark that the face of these mountains 

 on the south side, towards the sea, is generally abrupt and precipitous 

 (this is the case with most of the mountains of the Dicynodon forma- 

 tion), while on the north side, as seen along the road, the rocks are all 

 dome- shaped, or rounded and smoothed off, presenting a marked con- 

 trast to the opposite side. In the descent of the mountains on the 

 north side, on some of the shoulders and in a number of places at 

 high levels, are foimd large lateral accumulations of angular frag- 

 ments of rock, of various sizes, generally imbedded in clay. After 

 following the curvings of the long valley leading to Langfield, we 

 find large transverse mounds of drift and boulders, upwards of 60 

 or 70 feet high, that have afterwards been cut through where the 

 present watercourses run (see Section X). There are also large 

 deposits of unstratified clays, full of angular boulders of every size, 

 from small gravel and pieces of a few pounds' weight to masses of 

 several tons, turned and tilted into every position. I have not had 

 an opportunity of carefully examining these fragments for striae 

 or groovings. In several instances I have found transverse mounds, 

 rising like small hills, in far wider valleys, and many miles from the 

 high mountain-ridges whence the boulders have apparently come. At 

 the Bolotwa, in the valley in which the Mission -station is situated, are 

 a number of detached " kopjes," formed of large boulders piled to- 

 gether, and imbedded, as far as can be seen, in a matrix of stiff, 

 black, somewhat loamy clay. Here also the boulders are mixed 

 together indiscriminately: in some parts they are very compact, 

 and numbers are of many tons' weight. The largest of these mounds 

 has the side towards the top of the vaUey quite abrupt, and it there 

 rises to a height of some 70 or 80 feet. Prom the foot of this one 

 a bed of clay and boulders stretches for more than a thousand yards 

 through the Mission-station, where it appears to rest upon a loose 

 gritty sandstone (very similar to that at a place called the Bongolo 

 Neck, which I shall presently mention) in which large boulders are 

 imbedded. Again, some 12 miles nearer Queenstown there is a 

 high broken ridge of boulders, which the present watercourse of the 

 Inquobo (a torrent in rainy weather) cuts through at nearly a right 

 angle. A small section of this is exposed by a road-cutting ; and 

 in two places the boulders are found resting upon stratified rocks 

 (shale), whilst in another they lie on a bed of the same " whirled " 

 sandstone, with its imbedded boulders, as that at the Bongolo Neck 

 (see above) ; in some parts this ridge of boulders is from 900 to 1000 

 yards wide, and from about 90 to 100 feet high. 



About a mile and a half from this, the whole surface of the preci- 

 pice along the range of mountains on the south side of the road is 

 smoothed and rounded off in a very remarkable manner. This is 



