The Witwatersrand and Associated Beds (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905. Excerpt: ... The Witwatersrand and Swaziland Formations. The Upper Witwatersrand formation covers an area in the Southern Transvaal of approximately 640 square miles; and the Lower Witwatersrand formation, or Hospital Hill series, about 970 square miles. Thus, in this portion of the country, these two formations, which may be styled collectively The Witwatersrand beds, extend over some 1,600 square miles. They are also developed to a small extent in certain parts of the north of the Orange River Colony. Dr. Hatch (18) estimates the thickness of the Hospital Hill series at 8,000 to 10,000 feet; and, that of the Upper Witwatersrand strata at 11,000 to 15,000 feet. Dr. Molengraaff (56) gives the thickness of the former at Johannesburg as about 5,900 feet. De Launay (45) estimates the thickness of the latter at about 25,000 feet. These beds have their greatest and most typical development on the Witwatersrand, from which fact they have derived their name; and the alternative name of Hospital Hill series was given to the lower formation on account of the conspicuous development of its upper beds, especially the green quartzite and magnetic slate, on the hill at Johannesburg, immediately north of the town, on which the Hospital stands, and which is locally known as Hospital Hill. These two formations are conformable; the division is purely an arbitrary one, and for convenience is placed at the base of those conglomerates known as the Main Reef series. Along the Witwatersrand the strike of these beds is east and west, and their outcrop extends from the farm Randfontein, south-west of Krugersdorp on the far West Rand, to the farms Klipfontein and Cloverfield on the far East Rand, a distance of over 40 miles. The town of Johannesburg is situated almost exactly half-way between...