Drakensberg
The Drakensberg is the eastern portion of the Great Escarpment, which encloses the central Southern African plateau. The Great Escarpment reaches its greatest elevation – within the border region of South Africa and Lesotho.
File:The Escarpment and the Drakensberg.jpg|thumb|upright=1.4|A map of South Africa shows the central plateau edged by the Great Escarpment and its relationship to the Cape Fold Mountains to the south. The portion of the Great Escarpment shown in red is known as the Drakensberg.
The Drakensberg escarpment stretches for more than from the Eastern Cape Province in the South, then successively forms, in order from south to north, the border between Lesotho and the Eastern Cape and the border between Lesotho and KwaZulu-Natal Province. Thereafter it forms the border between KwaZulu-Natal and the Free State, and next as the border between KwaZulu-Natal and Mpumalanga Province. The escarpment winds north from there, through Mpumalanga, where it includes features such as the Blyde River Canyon, Three Rondavels, and God's Window. It then extends farther north to Hoedspruit in southeastern Limpopo where it is known as 'Klein Drakensberg' by the Afrikaner. From Hoedspruit it extends west to Tzaneen, also in Limpopo Province, where it is known as the Wolkberg Mountains and Iron Crown Mountain. At above sea level, the Wolkberg is the highest elevation in Limpopo. The escarpment extends west again and at Mokopane it is known as the Strydpoort Mountains.
Etymology
The Afrikaans name Drakensberge comes from the name the earliest Dutch settlers gave to the escarpment, namely Drakensbergen, or Dragons' Mountains. The highest portion of the Great Escarpment is known in Zulu as uKhahlamba and as Maloti in Sotho.Geology
Origins
The Great Escarpment is composed of steep rift valley walls formed around a bulging of continental crust during the breakup of southern Gondwana that have since eroded inland from their original positions near the southern African coast, and its entire eastern portion constitutes the Drakensberg. The Drakensberg terminate in the north near Tzaneen at about the 22° S parallel. The absence of the Great Escarpment for approximately to the north of Tzaneen is due to a failed westerly branch of the main rift that caused Antarctica to start drifting away from southern Africa during the breakup of Gondwana about 150 million years ago. The lower Limpopo River and Save River drain into the Indian Ocean through what remains of this relict incipient rift valley, which now forms part of the South African Lowveld.During the past 20 million years, southern Africa has experienced massive uplifting, especially in the east, with the result that most of the plateau lies above despite extensive erosion. The plateau is tilted such that it is highest in the east and slopes gently downward toward the west and south. Typically, the elevation of the edge of the eastern escarpments is in excess of. It reaches its highest point of over where the escarpment forms part of the international border between Lesotho and the South African province of KwaZulu-Natal.
Appearance
The escarpment seen from below resembles a range of mountains. The Limpopo, Mpumalanga, and Lesotho Drakensberg have hard erosion-resistant upper surfaces and therefore have a very rugged appearance, combining steep-sided blocks and pinnacles. Who first gave these mountains their Afrikaans or Dutch name Drakensberg, and why, is unknown. The KwaZulu-Natal – Free State Drakensberg are composed of softer rocks and therefore have a more rounded, softer appearance from below. Generally, the top of the escarpment is almost table-top flat and smooth, even in Lesotho. The "Lesotho Mountains" are formed away from the Drakensberg escarpment by erosion gulleys which turn into deep valleys containing tributaries of the Orange River. The large number of such tributaries give the Lesotho Highlands a very rugged mountainous appearance, both from the ground and from the air.The higher parts of Drakensberg have a mildly periglacial environment. It is possible that recent climate change has diminished the intensity of periglaciation.
Knight and Grab mapped out the distribution of lightning strikes in the Drakensburg and discovered that lightning significantly controls the evolution of the mountain landscapes because it helps to shape the summit areas – the highest areas – with this blasting effect. Previously, angular debris was presumed to have been created by changes typical of cold, periglacial environments, such as fracturing due to frost.
Composition
The geological composition of Drakensberg varies considerably along its more than 1000 km length. The Limpopo and Mpumalanga Drakensberg are capped by an erosion resistant quartzite layer that is part of the Transvaal Supergroup, which also forms the Magaliesberg to the north and northwest of Pretoria. These rocks are more than 2000 million years old. South of the 26°S parallel the Drakensberg escarpment is composed of Ecca shales, which belong to the Karoo Supergroup, and they are 300 million years old. The portion of the Drakensberg that forms the KwaZulu-Natal – Free State border is formed by slightly younger Beaufort rocks that also are part of the Karoo Supergroup.The Ecca and Beaufort groups are composed of sedimentary rocks that are less erosion resistant than the other rocks that make up the Drakensberg escarpment. Therefore, this portion of escarpment is not so impressive as the Mpumalanga and Lesotho stretches of the Drakensberg. The Drakensberg that form the northeastern and eastern borders of Lesotho, as well as the Eastern Cape Drakensberg, are composed of a thick layer of basalt that erupted 180 million years ago. That layer rests on the youngest of the Karoo Supergroup sediments, the Clarens sandstone, which was laid down under desert conditions, about 200 million years ago.
Geography
Peaks
The highest peak is Thabana Ntlenyana, at. Other notable peaks include Mafadi, Makoaneng at, Njesuthi at, Champagne Castle at, Giant's Castle at, Ben Macdhui at, and Popple Peak at, all of these are in the area bordering on Lesotho, which contains an area popular for hikers, Cathedral Peak. North of Lesotho the range becomes lower and less rugged until entering Mpumalanga where the quartzite mountains of the Transvaal Drakensberg are loftier and more broken and they form the eastern rim of the Transvaal Basin, the Blyde River Canyon lying within this stretch. The geology of this section is the same as, and continuous with, that of the Magaliesberg.Mountain passes
Ecology
The high treeless peaks of the Drakensberg have been described by the World Wide Fund for Nature as the Drakensberg alti-montane grasslands and woodlands ecoregion. These steep slopes are the most southerly high mountains in Africa, and being farther from the equator provide cooler habitats at lower elevations than most mountain ranges on the continent. High rainfall generates many mountain streams and rivers, including the sources of the Orange River, southern Africa's longest, and the Tugela River.These mountains also have the world's highest waterfall, the Tugela Falls, which has a total drop of . The rivers that run from the Drakensberg are an essential resource for South Africa's economy, providing water for the industrial provinces of Mpumalanga and Gauteng, which contains the city of Johannesburg. The climate is wet and cool at the high elevations, which experience snowfall in winter.
The grassy lower slopes of the Drakensberg in Eswatini, South Africa and Lesotho constitute the Drakensberg montane grasslands, woodlands, and forests ecoregion.
Flora
The mountains are rich in plant life, including a large number of species listed in the Red Data Book of threatened plants, with 119 species listed as globally endangered and "of the 2 153 plant species in the park, a remarkable 98 are endemic or near-endemic".The flora of the high alti-montane grasslands is mainly tussock grass, creeping plants, and small shrubs such as ericas. These include the rare Spiral Aloe ', which as its name suggests, has leaves with a spiral shape.
Meanwhile, the lower slopes are mainly grassland, but are also home to conifers, which are rare in Africa, the species of conifer found in the Drakensberg belong to the genus Podocarpus. The grassland is of interest as it contains a great number of endemic plants. Grasses found here include oat grass Monocymbium ceresiiforme, Diheteropogon filifolius, Sporobolus centrifugus, caterpillar grass ', Cymbopogon dieterlenii, and Eulalia villosa.
In the highest part of Drakensberg the composition of the flora is independent on slope aspect and varies, depending on the hardness of the rock clasts. This hardness is related to weathering and is variable even within a single landform.
Fauna
The Drakensberg area is "home to 299 recorded bird species"' making up "37% of all non-marine avian species in southern Africa". There are 24 species of snakes in the Drakensberg, two of which are highly venomous.One bird is endemic to the high peaks, the mountain pipit ', and another six species are found mainly here: Bush blackcap ', buff-streaked chat ', Rudd's lark ', Drakensberg rockjumper ', yellow-breasted pipit ', and Drakensberg siskin '. The endangered Cape vulture and lesser kestrel are two of the birds of prey that hunt in the mountains. Mammals include klipspringer ', eland ', and mountain reedbuck '. Other endemic species include three frogs found in the mountain streams, Drakensberg river frog ', Phofung river frog ', and Maluti river frog '. Fish are found in the many rivers and streams, including the Maluti redfin that was thought to be extinct before being found in the Senqunyane River in Lesotho.
The lower slopes of the Drakensberg support much wildlife, perhaps most importantly the rare southern white rhinoceros and the black wildebeest. The area is home to large herds of grazing fauna and antelopes such as eland ', reedbuck ', mountain reedbuck ', grey rhebok ', and even some oribi '. Chacma baboons also are present. Endemic species include a large number of chameleons and other reptiles. There is one endemic frog, the forest rain frog ', and four more species that are found mainly in these mountains; long-toed tree frog ', plaintive rain frog ', rough rain frog ', and Poynton's caco .