National Geographic : 1896 Nov
THE WITWATERSRAND AND rocks are of Paleozoic age, but carry no fossils. The conglom erates of this group almost all contain more or less gold. The most famous mines of the Transvaal are opened upon a certain set of these conglomerate beds known as the Main Reef series. Resting unconformably on the Lower Cape is another group known as the Upper Cape and containing one bed of conglom erate, the Black Reef, which has been profitably worked for gold at some points. An extensive sheet of dolomite forms one mem ber of the Upper Cape. Unconformably on the Upper Cape lies the Triassic, carrying very extensive beds of coal, one of the treasures of the Transvaal of which little is heard outside of South Africa. As the country is also rich in iron ores, one may expect to hear more in the future than in the past of these coal fields. Meantime they supply the gold-mining industry with good and cheap fuel. The Lower Cape formation, with the Main Reef series, is exposed only to a limited extent. Within less than 20 miles of Johannesburg, both to the east and west, the Upper Cape and the Triassic beds flood the country, and for a long dis tance only an occasional glimpse is to be had of the Lower Cape with its auriferous conglomerate. It is said by various engineers to reappear occasionally for hundreds of miles from Johannes burg-as, for instance, in Zululand-and to be more or less aurif erous wherever found. It need hardly be remarked that the search for the Main Reef beneath the Trias is most arduous. That it will eventually be traced far beyond the surface exposures of the district is quite certain. In this paper the Witwatersrand district alone is of especial interest, but in conveying a general notion of the Transvaal it must be remarked that this is by no means the only auriferous district in the republic. There are four other districts, contain ing in all ten mines, which yield at the rate of over $100,000 each annually. Of these the Klerksdorp district carries gold in conglomerates. In the three other districts the gold is found in ordinary veins. The Sheba mine, in the De Kaap district, has yielded over $5,000,000. Four of the important mines lie in the Lydenburg district, and one, the Sutherland, in the Zoutpans burg district. The total gold product of the Transvaal for 1895, outside of the Witwatersrand, was $3,581,000, while the Rand alone yielded $38,110,000.* Statistics show that the yield of the outside mines is increasing about as rapidly as that of the Rand. * For comparison it may be noted that the United States produced in 1895 $46,610,000 worth of gold, or about $4,900,000 more than the Transvaal.