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 (crater) of its craters exceeds the critical crater diameter. This would explain the crowding of giant craters, since none of these would result in global degradation. Indeed, if Karoo, at 33 km diameter, represents D and resurfaced the asteroid, then the 5 or more other giant impacts must have happened subsequently, which is highly unusual given that they are in fact almost just as large. Thus α = 1.33 from Fig. 2a is likely a lower limit on Mathilde’s attenuation. Karoo (crater) Karoo is an impact crater on the Asteroid 253 Mathilde, named for the Great Karoo Basin, a coal basin