The Forming of the DraJcensberg. 59 



If we choose a locality such as Jamestown, where well-preserved 

 fern fossils can be obtained, we find that the Molteno beds extend 

 round about it for a distance of fifty miles at least, and similar plants 

 can be got at Molteno, Herschel, Engcobo, &c. 



That is to say, plants occur in the beds over an area with a 

 diameter of one hundred miles, and yet specimens from the centre 

 are in as good condition as those obtained from points on the 

 circumference. Clearly, then, by being drifted an additional distance 

 of fifty miles the plants were not appreciably injured. An examina- 

 tion of the sandstone beds, on the other hand, shows that the plant 

 remains are nearly always more or less fragmentary, and that, too, 

 in any part of the area. Consequently the condition of the fossil 

 ferns in the beds gives us no help in estimating the distance they 

 must have drifted before they were ultimately entombed in the 

 sediment. 



These plants, together with other vegetable material, have gone to 

 form the coal seams of the Molteno beds. By some geologists each 

 coal seam is supposed to represent an old land surface, or, more 

 properly speaking, a swampy tract of land where the vegetation 

 grew and was afterwards buried. 



I am, however, a strong supporter of the theory of the sub- 

 aqueous origin of the Stormberg coals vigorously upheld by Green 

 and Galloway. According to this view, the coal seams do not 

 indicate former land surfaces, but simply unusual phases of sedimen- 

 tation, during which finely-divided carbonaceous material was 

 deposited along with a varying amount of finely-divided matter of 

 detrital origin. In this way we get all gradations from mudstone 

 and shale to coal, while sometimes we get very rapid alternations of 

 coaly and shaly material, giving the coal a finely laminated 

 structure. 



The carbonaceous material was deposited in fairly shallow water, 

 in which the currents were often strong. This explains their local 

 character, for the soft, pulpy vegetable matter would be easily 

 carried away by currents. At Indwe these currents have been laden 

 with coarse sediment, and in places several feet of coal and shale 

 have been removed and their place taken by the gritty material. 

 False-bedding is common in these grits, and now and then little 

 lenticular seams of coal and shale occur, sometimes wavy and 

 contorted. 



It is significant that the most important coal seams are found to 

 the south and south-east of the Stormberg area, namely, Molteno, 

 Indwe, Engcobo, Maclear, &c, while in Aliwal North, Herschel, and 

 Rouxville coals are infrequent, thin, and of very poor quality. 



