Karoo historical Karoo described in South African atlases and guide books (compare the map on the right with the map at the beginning of the article). The Succulent Karoo biome runs along the West Coast, from approximately Lamberts Bay northwards to over 200 km into southern Namibia. It starts in the south just north of the Sandveld geographical region, about 250 km north of Cape Town, and continues through Namaqualand, the Richtersveld, immediately south of the Orange River, and on into the Namaqualand or Namaland region of southern Namibia. None of these regions is ever referred to, either geographically or locally,
Karoo Group (i.e. the oldest layer of the Cape Supergroup). The valley floor is covered, in the main, by the next (younger) layer of the Supergroup, namely the much softer Bokkeveld shales. The dolerite of the Great Karoo did not penetrate these rocks, so Karoo Koppies are not seen in the Little Karoo. The Little Karoo contains two other geological features that give the landscape a special character. During the erosion of the African interior following the bulging of the continent during the massive lava outpourings that ended the Karoo sedimentation 180 million years ago, some of the eroded material was