What are popularly termed the Banket Beds of Johannesburg have for years past been justly celebrated for their extraordinarily large and steady gold production. Their literature has already assumed formidable dimensions, so it is unnecessary for my present purpose to give a detailed account of the features they present. They form part of what is generally known as the Witwatersrand Series, which consists of highly altered sandstones and conglomerates almost certainly of Archæan age. They unconformably overlie the banded rocks known as the Hospital Hill Beds, and are overlain by the Dolomite, often termed the ‘Olifants Klip’ or ‘Elephant Rock.’