( 67 ) 
NOTES ON THE DWYKA COAL MEASURES AT 
VEREENIGING, TRANSVAAL, Evc. 
By EH. J. Dunn, F.G.S. (Lond.) 
(Plate I.—Map.) 
SITUATION, Etc. 
The Vereeniging coal-mines are situate on the north side of the 
Vaal River where the railway crosses the river between Johannesburg 
and Bloemfontein. Height above sea-level at the station is 4,750 
feet. The surface below which the coal occurs is fairly level. On 
the south side of the river is the Cornelia coal-mine, about 14 miles 
distant from the Vereeniging shaft. These mines are opened up 
and worked on a large scale, having a daily output of about 1,000 
tons of coal. Jam indebted to the courtesy of the owners and the 
manager, Mr. Goodwin, for the opportunity of examining the geo- 
logical evidence laid bare in the workings. 
GEOLOGY. 
Along the railway line from Elandsfontein to Vaal River, the Rand 
Beds of auriferous conglomerates, quartzite, shales, and intercalated 
diabase rocks are crossed for a few miles, then a belt of Lydenburg 
Beds (dolomite) until 2 miles south of Meyerton Station, where the 
Dwyka conglomerate crops out and the coal measures. Southward 
from this the Dwyka conglomerate and accompanying coal measures 
go underfoot, and they do not crop out again at the surface for 
hundreds of miles; they reappear on the south side of the basin 
running from Matjesfontein past Prince Albert to Grahamstown. 
The western, southern, and eastern extension of the Dwyka con- 
glomerate was laid down in my report to the Cape Government in 
1886, and the northern limit is now added in the accompanying 
plan. 2h 
The Dwyka conglomerate is directly overlaid by: the black 
carbonaceous shales all round the enormous area enclosed by that 
rock ; at Kimberley these shales attain a thickness of 240 feet, and 
some of the beds carry 9 per cent. of carbon. At Vereeniging the 
coal seams lie either immediately upon the conglomerate or there is 
black shale intervening for a few feet with black shale again above 
the coal. It follows that the Dwyka conglomerate is a splendid 
