Notes on the Dwyka Coal Measures at Vereeniging, Transvaal. 69 
seams of abnormal thickness is being turned out in thousands of tons 
weekly in the Transvaal and Natal. 
These great seams that are being worked so extensively in the 
Transvaal dip away underfoot in the Free State, and should be cut 
at about 1,500 feet at Bloemfontein. In the Cape Colony a bore 
where the railway crosses the Orange River from Kimberley should 
cut the coal measures within 300 to 400 feet or less. The dip of the 
coal measures from Kimberley is southwards, and near De Aar on 
the one side of the high ground and Cradock on the other are the 
likeliest points upon the Port Elizabeth to Kimberley line at which 
bore-holes should succeed. 
Mr. A. R. Sawyer, of Johannesburg, has not only bored extensively 
over the South Rand coal-field, but he has also sunk a large shaft 
582 feet deep here, and opened out upon a seam of coal 54 feet thick 
having a thin parting of sandstone 12 feet from the top. This coal 
is reported of excellent quality. Here sandstone, shale, and dolerite, 
to a thickness of over 100 feet, intervene between the coal and the 
Dwyka conglomerate below, but they appear quite conformable, and 
this negative fact has no weight against the positive evidence 
afforded at Vereeniging. Mr. Sawyer most fully endorses the view 
that his coal seam is of Sub-Karroo age, and his borings amply 
confirm this view. At Vereeniging the results of over twenty borings 
were placed at my disposal, and out of these eight showed the coal 
resting directly upon the Dwyka conglomerate, in the others black 
shale from 1 to 19 feet thick intervened. 
At Vereeniging the Dwyka conglomerate consists of angular 
fragments, boulders, pebbles, &c., of quartzite, sandstone, shale, 
chert, dolomite, diabase, &c., and conglomerates both from the Rand 
Beds and the Lydenberg Beds, all such materials as might be 
derived locally, and ranging in size from grains of sand up to two and 
three hundredweight a piece. This material lies scattered without 
order or arrangement through a fine light grey clay, which is used 
extensively for making firebricks, &c., and locally termed fireclay. 
This Dwyka conglomerate shows by its general condition, by the 
forms of the included boulders, &c., and by the striated faces of the 
pebbles, boulders, &c., that it is of glacial origin. There appears to 
be a rude kind of bedding observable where this conglomerate is 
excavated for making firebricks as though it had been deposited in 
water. However deposited, there can be no doubt as to its being of 
glacial origin. 
The very important point is that the upper portion of the con- 
glomerate shades by degrees mto a carbonaceous shale in places, 
further, root-markings of carbonised matter penetrate into the con- 
