Page:South African Geology - Schwarz - 1912.djvu/154

 Sandstone was always next to the Malmesbury Beds, and the top next to the Bokkeveld Beds, however much the rocks were folded. If a mountain of Table Mountain Sandstone appears above a plain of Bokkeveld Beds it does so because an anticline brings up the lower beds through the upper; whereas if such a mountain lies in a plain of Malmesbury Beds it is a syncline that has brought the upper beds down to the level of the lower.

The soil in the Bokkeveld is sweet, and is covered with cornlands and vineyards. In the drier parts it bears the peculiar Karroo vegetation, where the plants, instead of spreading their roots through the soil on the surface, have to send them down through crevices where a little soil and moisture is to be found; in other words, the surface is bare rock and the soil is underground.

The Witteberg Series is a series of thin-bedded, close-grained, yellow sandstones, with partings of micaceous red shale. Indeed, one can say it is a fourth white sandstone of the Bokkeveld Series, and the two series have very much in common. Between the last band of quartzite in the Bokkeveld Beds and the first great series of quartzites in the Witteberg Beds there are some 800 ft. of shales. The line of division between the two series is taken in the middle of the shale, as it is here that the fossil, Spirophyton, first becomes plentiful. It forms the lower hills in front of the great coastal mountains, and is separated from them by a valley of Bokkeveld Beds. It was formerly confounded with the Table Mountain Series. Apart from the fact that it lies above, not below, the Bokkeveld Beds, the differences may be tabulated thus: —