Karoo an immense volume of rocks which was formed, geologically speaking, in a short period of time. Although almost the whole of the Great Karoo is situated on Karoo Supergroup rocks, the geological Karoo rocks extend over a very much larger area, both within South Africa and Lesotho, but also beyond its borders and onto other continents that formed part of Gondwana. The Karoo Supergroup was formed in vast inland basin starting 320 million years ago, at a time when the part of Gondwana which would eventually become Africa lay over the South Pole. Icebergs that had calved off the glaciers
Karoo into the increasingly arid Bushmanland towards the north-west. To the north and north-east, it fades into the savannah and grasslands of Griqualand West and the Highveld. The boundary to the east grades into the grasslands of the Eastern Midlands. The Great Karoo is itself divided by the Great Escarpment into the Upper Karoo (generally above 1200–1500 m) and the Lower Karoo on the plains below at 700–800 m. A great many local names, each denoting different subregions of the Great Karoo, exist, some more widely, or more generally, known than others. In the Lower Karoo, going from west to east,