Page:South African Geology - Schwarz - 1912.djvu/144

 manifest that the beds, which cannot as a whole be more than a mile or so in actual thickness, have been bent upon themselves many times. At Van Rhynsdorp, again, limestone bands come in. There are swallow holes, showing that there must be caverns in the limestone, but as the rock is exposed in a flat plain there are no openings, like in the hilly district of the Cango, by which one can explore them.

Above the closely folded Malmesbury Beds at Van Rhynsdorp there comes in another series of clay slates very little folded, the Ibiquas Series, so called from the name of the tribe of Hottentots that once lived here. Below the Malmesbury Beds, there is a series of red sandstones and arkoses, called the Nieuwerust System, which underlies extensive areas in Narnaqualand. Inland, on the north of the Karroo, Pal-Afric beds come in again; but these belong to the Transvaal area, and will be described under the section dealing with that area.

Granite Intrusive in the Malmesbury Beds. — Great domes of molten rock have invaded the Malmesbury Beds all over the area in which they are exposed, and these have solidified as granite. In some places, as at the Paarl and Malmesbury, the rock has resisted weathering so successfully that all overlying rocks and the softer slates which surround it have been cleared away, and the granite dome rises as a magnificent mountain. At other places, as at Simon's Berg, and especially at Cape Town, the granite is still capped with the overlying Table Mountain Sandstone. At still other places, as, for instance, at George, the granite has been worn down equally with the slates, and there is no difference in the relief of the country where it occurs. At Worcester, and the same is