GEOLOGY OF THE SOUTH AFRICAN REPUBLIC II 
relations to each other there is some difference of opinion among 
geologists. They may be separated into three groups. 
1. Zhe Quartzite and Shale group of Gibson (Magaliesberg 
beds of Penning) underlying the auriferous conglomerates north 
of Johannesburg, and considered by Gibson to belong to the 
same series, though separated by a fault, which Molengraaf holds 
to be an unconformity. 
2. The great series of auriferous conglomerates. 
3. A series of Jdlue dolomites, alternating with siliceous or 
cherty beds. Those which occur in the Malmani district, to the 
west of Johannesburg, Molengraaf considers to be the upper 
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Section across Rand. 
part of the Cape formation, while immediately north of Johannes- 
burg similar dolomites underlie a series of quartzite and shales, 
which Schenck considers to correspond to those directly beneath 
the auriferous conglomerates. These dolomites have a wide 
distribution in the Western Transvaal and extend into Bechuana 
land. 
The general relations of these beds is shown in a section 
given by Hatch, which is apparently drawn to scale, and extends 
from the Magaliesberg on the north, through Johannesburg, to 
the Black reef beds onthe south, a length of over twenty miles. 
On the line of this section immediately to the north of Johannes- 
burg, are the quartzites and shales, the former standing out as 
east and west ridges between shale valleys. They have a steep 
dip to the south, and are succeeded to the north by granite and 
schists, supposed to correspond to the Swasi-schists. To the north 
of the granite, and dipping northward away from it, are the 
dolomitic limestones of the Kalkheuvel range; beyond these 
again, still dipping north, is a series of quartzites and shales 
