THYSICAL GEOGRAPHY OF THE CAPE COLONY. 257 



quite as much entitled to the appellation as the Zwartebergen and 

 the Wittebergen. 



This great group of horizontally bedded rocks abuts on the north 

 against the mass of crystalline schists that range from Eushmans- 

 land into the Transvaal (see northern end of Section 2, fig. 5). 



To pass to details, the general structure of the country south of the 

 Zwartebergen and Wittebergen range is shown on Section 2 (fig. 5). 

 This part of the section is mainly taken, with some modifications, 

 from Bain ; but I was able, during the railway- journey across the 

 country which it traverses, to observe enough to assure me of its 

 general correctness. It makes no pretensions however to be any- 

 thing more than a mere hand-sketch. 



In the south of this strip of country the hills run up to some 3000 

 or 41)00 feet above the sea, and the beds undulate in broad saucer- 

 shaped basins. As we go northwards the ground rises, the folds 

 become sharper till they pass into what may fairly be called con- 

 tortions, and we reach the zone already mentioned, in which 

 contortion and elevation reach their maximum. It is a long 

 mountain-belt formed by the Zwarteberg Quartzites, the highest 

 points of which run up to between 6000 and 7000 feet above the 

 sea. I made four traverses across this range : between Aberdeen 

 road and Port Elizabeth ; between Port Elizabeth and Grahams- 

 town ; on my road from Aberdeen into the valley of the Oliphants 

 River ; and on my return from that valley to Prince Albert. The 

 physical structure was everywhere the same : long lines of rugged 

 and lofty hills formed of very contorted synclinals of quartzite, cut 

 across every here and there by deep transverse gorges, and between 

 the hill-ranges great longitudinal valleys, which run along very con- 

 torted anticlinals of shales and sandstones on which the Quartzites 

 rest. 



I think there is little doubt that these shales and sandstones belong 

 to the Bokkeveldt Beds. Mr. T. Bain told me that the fossils of that 

 group had been found in them, and I noticed badly preserved shells 

 in them near Willowmore. I have therefore represented them as 

 Bokkeveldt Beds on the sections. Section No. 3 (fig. 6) will give a 

 good general notion of the structure of the Quartzite-belt. 



By far the finest section which I saw was in Meirings Poort, 

 between Prince Albert and the valley of the Oliphants River. This 

 is a narrow^ precipitous gorge, in parts almost deserving the name 

 of caiion, trenching one of the great quartzite-ridges down to its 

 very base. The sides run up in a succession of steep steps to heights 

 which must be, in places, several thousand feet above the floor of the 

 gorge, and in the vertical walls at the bottom an almost unbroken 

 section is laid bare. The thickly-bedded Quartzites stand up for 

 the most part nearly on end, and are only moderately folded ; but 

 interbedded bands of more thinly-bedded sandstones and shales are 

 crumpled in the most violent manner, and often so mashed up that 

 it was not possible to follow any single bed for even a moderate 

 distance. 



I did not see enough of the country which has been so far described 



