which, are outlets such as I have described, extend for miles accumulations of drift and boulders, very different from regular fluviatile deposits ; and which seem to indicate that the erosion of the channels in question arose from other causes than those at present in operation in South Africa*.
North of the Stormberg. — On the northern side of the Stormberg, at Dordrecht and the Hot-Spruit (a branch of the Orange River), the same features are equally observable, — the peculiar wearing of the rocks ; the large accumulations of unstratified clays, mixed with patches of drift and boulders, both angular and waterworn ; and the rounding of the hills that face the interior of the valleys. I have not yet visited the district of the Washbank ; but Dr. Meintjes informs me that among the mountains there, and which are the highest portions of the Stormberg, there are distinct traces of both lateral and terminal moraines. In a valley near Ladygrey, some 4 or 5 miles wide, he found in the centre a patch of twelve or fourteen enormous angular boulders, standing from 10 to 12 feet out of the ground, and nearly the same in length and breadth. It would have been impossible for water to have moved these masses of rock to such a place†. The evidence in this part of the mountains would refer to far more recent operations than those of which we ' have before spoken, as the last retreat of the glaciers would be along this range, before the gradual change of climate caused their final disappearance.
British Kaffraria. — Besides the evidence here brought forward, there can be little doubt that an indefinite number of instances of the same description might be collected among these mountains. Not only here, but if we turn to the present coast we there find numerous evidences of the same action that cannot be explained as having occurred through the ordinary agency of water. Within a few miles of Grey town, in British Kaffraria, there is a very remarkable dome-shaped rock, situated on a neck or opening through a high ridge, near the Kabousie. The rock runs across a portion of this neck, and is completely rounded ; it is about 350 yards long, and from 60 to 70 feet high. A number of huge boulders are scattered about, as will be seen from the Sketch AC and Plan AE, kindly furnished me by Mr. T. Liefieldt, Resident Government-Agent of the Gaika Tribes. The high ridge on both sides of the neck is perfectly smooth, and no other rocks are visible for miles.
Kaga and Krome Mountains. — On the southern side of the Kaga and Kroome mountains, branches of the Great Winterberg, we also obtain evidence indicating that other agencies have been at work besides those of a purely aqueous nature. Extensive flats are
- See the late R. N. Rubidge's paper on pluvial denudation in South Africa.
Geol. Mag. No. 20, Feb. 1866, p. 88.— T. R. J.
† I have frequently seen large angular boulders, 10-12 feet in diameter, with the uncovered part 9 or 10 feet out of the surrounding clay, in the centre of a wide valley, where it would be impossible to explain how such ponderous masses could have been transported by the force of water.
