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 chat similar grey form of the female mountain wheatear, from which it also differs in having a grey (not white) rump and completely white outer tail feathers. Its larger size and all-white outer tail feathers prevent confusion with the tractrac or sickle-winged chats. The Karoo chat has "chak-chak" and "trrat-trrat" calls. The Karoo chat builds a cup-shaped nest of straw and leaves on the ground, usually under a bush or shrub. It lays two to four green eggs. This species is monogamous, mating for life. The Karoo chat is usually seen singly or in pairs. It forages from the ground for