Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/693

This page needs to be proofread.

palpable powders of different colours, from which the ancient Bushman race (now rapidly becoming extinct) obtained many of the pigments they used in their cave-paintings. This noduliferous sandstone lies on the quartzose grit (D. S. 1 *, in some places almost a conglomerate), No. 7, ten feet thick, and composed of quartz, which could only have come from the Washbank. Below this is the coarse sandstone of the " Forest-zone," No. 8, with " silicified " trees, probably coniferous, at least thirty feet long. No. 9 is a much finer-grained sandstone, and of a darker colour. Great numbers of what appear to be casts of roots† , are obtained from this deposit. Sometimes they are soft and easily pulverized ; and when found in that state they were ground down and used by the Bushmen as a fine dark chocolate paint, frequently used by them in delineating the human figure in their caves. The height from the lowest exposed stratum to the basaltic blocks is about 450 feet."

The discovery of stratified clays below these beds was made in sinking a well in the village of Dordrecht ; and although no intervening section has yet been obtained, it seems very probable that they are conformable. For six or eight feet the upper clays are of a bright-yellowish colour, No. 10, with abundance of Pecopteris (?) and other plants. I secured a large case of them ; but, unfortunately, during its transit it was saturated with rain, and these beautiful specimens were destroyed‡. Below, the clays (from seven to eight feet thick) are of a light-grey colour, No. 11 ; here the Ferns &c. are not so abundant. Below this there is a dark bluish-grey clay, No. 12, much more compact than those above, and from ten to twelve feet thick ; in this the leaf-impressions are far less numerous. I am not aware whether or not these clays appear at the surface at a lower level.

The dip of the strata in the section just described is 6° or 7° S.E., and they are probably some of the most recent on the northern portion of this great basin of deposit.

Section on the Upper Zwart Kei. — The section, fig. 9, is from the

  • " D. S. 1." Round lump of coarse quartzose grit (some of the grains

rounded), with some felspar and a little mica, feebly cemented with iron-oxide and some clay.— T. R. J.

† The specimen sent represents, in fragments, a long subcylindrical concretion (?) of amorphous chocolate-brown haematite, striated longitudinally outside, and here and there showing traces of concentric structure within. Specimens of the enclosing rock, sent with the above, consist of ferruginous sandstone, with indeterminable casts and markings. — T. R. J.

‡ Mr. Carruthers, F.R.S., of the British Museum, having examined the specimens here referred to, has kindly supplied the following note : —

" The specimens from Dordrecht are not satisfactory. Among them are three species of Ferns, which, I believe, are new. One seems to be a species of Danoeopsis, a second a Sphenopteris ; and I know not what fossil genus I could refer the third to. With these are associated what appear to be fragments of a monocotyledonous plant, which are undeterminable.

" It is not improbable that a set of these Ferns would comprise specimens with fructification ; and this would be very important. The fragments before me have been so much injured by the water which had access to them that they are little more than determinable as Ferns.

" The woods are all, I believe, Coniferous. — W. C, April 10, 1871."