Karoo Supergroup of the country, and in the Lebombo mountains along the Mozambique border. Once the layer of hard lava was eroded away, the softer Karoo sediments over the rest of the basin eroded even faster. However, the dolerite sills resisted erosion, protecting the softer Beaufort and Ecca shales beneath them. This created numerous and widespread flat topped hills, known as Karoo Koppies ("koppie" being the Afrikaans term for hill), which are iconic of the Karoo, and, by extension, the South African landscape. The dykes, or vertical fissures which brought the lava to the surface stand out today as linear ridges extending
Karoo Karoo is distinctively divided into the Great Karoo and the Little Karoo by the Swartberg Mountain Range, which runs east-west, parallel to the southern coastline, but is separated from the sea by another east-west range called the Outeniqua–Langeberg Mountains. The Great Karoo lies to the north of the Swartberg range; the Little Karoo is to the south of it. The only sharp and definite boundary of the Great Karoo is formed by the most inland ranges of Cape Fold Mountains to the south and south-west. The extent of the Karoo to the north is vague, fading gradually and almost imperceptibly