Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/700

 This section is from that part of the mountains where the Klaas- Smit's River (the "Hokili" of Hall's Map) takes its rise. The better to explain its position relatively to the two others previously described, I send a rough sketch-map of the intervening country, (fig. 12).

The lowest exposed stratum (1, 1) is a rather dark brownish-red shale, about 150 feet thick, full of minute specks very much resembling mica. On this is a very fine-grained greyish sandstone. It forms a precipice about 40 feet high ; and this is the case with every succeeding sandstone, the shales sloping from the one sandstone to the foot of the other, which rises at once precipitously 40 or 50, and, in the case of stratum No. 6, nearly 75 feet, forms a kind of terrace a few feet wide, or, as on the surface of the last-mentioned stratum (6), one of several yards in width, and then slopes up again to the foot of the next sandstone at the higher level. No. 3 is a shale of about the same thickness as the one below, and very similar in character, except that it is of a lighter colour. Upon this rests a sandstone (4) containing abundant impressions of leaves and very thin layers of fossil wood. The next shale (5) is still lighter in colour than the preceding one. Over this is No. 6, a rather gritty, light- brown sandstone, also containing numerous impressions of leaves, similar to those found in No. 4, as well as fossil wood ; also streaks of fine coal and black hardened shale. These small patches of coal appear to have been accumulations of vegetable matter in hollows on the uneven surface of the sandstone beds at the time of deposition. Above this is a bed (7) about one foot thick, composed of thin layers of a light-brown hard shale ; a number of thin alternate layers (No. 8) of light-coloured shale and coarse sandstone, containing round nodules and pieces of fossil wood, succeed. These nodules contain the same kind of ochres as some of those found in the Dordrecht section (page 525), the contents of which were made use of by the Bushmen. Next comes a thin sandstone (No. 9), and upon that six feet of black shale (No. 10), containing a number of seams of coal varying from an inch to a foot in thickness. This is the " Stormberg coal deposit." I have seen a spot where this coal-shale is 14 or 15 feet thick. It is found cropping out at intervals for many miles along the face of the mountains ; it also reappears on the northern side of the range ; but the sections on that face have not yet been examined. In this deposit (at 11) there is a remarkable band of very fine yellow and white pipe-clay, about two or three inches thick, its colour offering a marked contrast to the black shale and its accompanying coal-seams. No. 12 is a stratum of bluish-brown clay, almost shaly. No. 13 is a gritty ferruginous sandstone, containing nodules (very similar to those sent as specimens from Dordrecht) and quartz-pebbles. Upon this lies No. 14, consisting of a thick band of ironstone nodules. It has been thought that the infiltration through these strata, especially No. 13, into the coal-shales below has injured the quality of the coal found in them by impregnating it with mineral matter, from which that found in No. 6, in the small