Page:South African Geology - Schwarz - 1912.djvu/183

 lion, antelopes, owls, mice, &c., which are found in the caves in the lead and zinc carbonates at Broken Hill, Rhodesia.

The sand dunes are of several ages, the older series forming consolidated masses of limestone of great extent in Saldanha Bay, Bredasdorp, Riversdale, Knysna, and at the Bluff at Durban. The dunes are 600 ft. high, and from Cape Agulhas to the Gouritz River form a strip from 10 to 15 ml. broad for a distance of 120 ml. Some of the dunes are very old, and the shell sand has broken down to a continuous chalky deposit, in which bones of extinct types of horse, and of great antelopes, elephants, rhinoceros, and so forth, which now live far to the north, are embedded. More recent dunes occur on the seaward side, and over the flat surf-cut shelf which separates the Cape peninsula from the mainland.

TRANSVAAL-BECHUANALAND

This area is a very much older one than the Cape area. On all sides there are present the gneisses, schists, and extremely ancient slates with intrusive granite, which we called the Malmesbury Beds in the previous section. Lying folded upon these are series of less metamorphosed sediments called the Witwatersrand System in the Transvaal and the Kheis System in the west. Upon these again lies a threefold system, the Transvaal System, very little disturbed; and again upon this comes the Waterberg System. All these are unfossiliferous, and are included in the Azoic. The last two systems, the Transvaal and Waterberg, are characterized by vast outpourings of lava, and when the Waterberg Beds had been hardened into sediments an