Page:South African Geology - Schwarz - 1912.djvu/155

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STRATIGRAPHICAL GEOLOGY
145

DIFFERENCES BETWEEN THE WITTEBERG AND TABLE MOUNTAIN SANDSTONES

Witteberg Sandstone Table Mountain Sandstone
Fine-grained, thin-bedded, yellow sandstones; shale partings throughout. Coarse-grained, massively bedded, grey sandstones; shale bands only at top and bottom.
Fossils : Lepidodendron, Spirophyton, Hastimima. Example No fossils; indistinct traces of shells in the shales at the base.

The Witteberg Beds are usually intensely folded, the thin sandstones readily accommodating themselves by that means to stresses, whereas the Table Mountain Sandstone, as a rule, bends into great arches. The close nature of the sandstone prevents the penetration of moisture, so that the coarse-grained Table Mountain Stone is more plentifully supplied with springs than the Witteberg. This character also leads to the rocks, when they are tilted, being exposed in enormous flat slabs. The name of the series is derived from those slabs that face the Karroo, and which are exposed by the overlying Dwyka shales having been removed from off them, but a similar feature is exhibited in the Table Mountain Sandstone in Ceres. Bands of white quartz pebbles may also be present in the Witteberg Sandstone, and towards the top of the series there is usually, in the west at least, a well-marked shale band followed by the top quartzites exactly on the same lines as in the Table Mountain Sandstone. The differences between the two series, however, are too great to allow these resemblances to puzzle anyone who has had them pointed out.

The fossils of the Witteberg beds are extremely important, as they are the same as those found in the Coal Measures in Europe and America, namely, lepidodendroid stems. The actual stems are usually Bothrodendron,