Karoo are exposed. These are locally known as the Cango Group, but are probably continuous with the Malmesbury Group that forms the base of Table Mountain on the Cape Peninsula, and similar outcrops in the Western Cape. In the Little Karoo, the outcrop is composed of limestone, into which an underground stream has carved the impressively extensive Cango Caves. The Great Karoo and Little Karoo lie almost entirely within two of South Africa’s eight botanical biomes, namely the Succulent Karoo biome and the Nama Karoo biome, both of which, like the Karoo Geological System, are more extensive than the geographical or
Karoo the winter. Grasses are uncommon, making most of the biome unsuitable for grazing. The low rainfall, in fact, discourages most forms of agriculture. An exception is the thriving ostrich-farming industry in the Little Karoo, which is heavily dependent on supplementary feeding with lucerne. The difference between the Succulent Karoo biome and the Nama Karoo biome is that the former receives the little rain that falls as cyclonic rainfall in winter, which has less erosive power than the infrequent but violent summer thunderstorms of the Nama Karoo. Frost is also less common in the Succulent Karoo biome than in the Nama