Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/708

 just at a bend or shoulder, where a glacier, descending from the northward, would press with the greatest force before turning off to the watershed of the Komani or Inquobo just mentioned. But there are many places where these rounded or dome-shaped rocks are to be found. Thus among these same mountains, near where the Zwart Kei passes through, they are found on both sides of a gorge forming an outlet to an auxiliary branch of that river, near a farm occupied by Mr. Lenard, and through which is an outlet to a basin as large as, although more irregular in shape than, those of Schaap Kraal and the Bongolo (see below). Of this outlet I have sent a sketch (Y). Here the rocks are perfectly rounded off to the height of several hundred feet ; it is impossible to imagine how water alone could have produced such an effect. Rocks with similar features occur in another precipitous glen, forming the outlet of a large valley-basin called Schaap-Kraal Hoek (vide infra), near Tarkastad. In this case, on the one side all the rocks are smoothed and rounded, while on the opposite side are beds of unstratified drift intermixed with immense angular boulders. And here, again, we find a portion of this boulder- clay resting upon the same kind of sandstone, with its imbedded boulders and fragments of rock, as at the Bongolo Neck.

Another notable instance of these dome-shaped rocks I noticed on the road from the Rhenosterberg to Cradock. They were outliers, forming small, rounded, bubble-like hills in the middle of a wide flat valley some miles broad.

Basin-like valleys, their moraines, striae, &c. ; Schaap-Kraal Hoek. — Another remarkable feature in the denudation consists of so-called flats, but really basins, which seem to have been scooped out of the horizontal strata. It is very difficult to understand how they could have been so excavated by the simple agency of water, or the ordinary atmospheric influences of any climate except an antarctic one. Thus a place before mentioned, Schaap-Kraal Hoek, is an elevated valley some 12 miles long and 6 or 8 broad ; it is surrounded on every side by a continuous range of mountains. The outer face of all these mountains is exceedingly abrupt and precipitous, whereas within the basin no precipitous rocks are to be seen ; the sides are all smoothed off, gradually sloping from the highest ridge towards the centre, as if the strata that had once filled the intervening space had been scoured out. The inner face of the highest rocks, columnar on the outer precipices, shows lines of stratification. (See section, fig. 15.)

As the elevation of this valley is so near the level of the original plateau, without any inlet through which water could have flowed, one cannot imagine but that the denuding power must have been some such agent as ice that accumulated within the basin itself. Before the eroding of the outlet described above, a far more ancient one existed where the road now passes towards Buissen's Spruit, a branch of the Eland's River, and at the extremity opposite to the present outlet. At both these outlets, where they debouch into the lower country, the mountain-sides are loaded, to the height