Drakensberg
The Drakensberg is the name given to 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.
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 Drankensberg' 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 to the region gave to the escarpment. Thinking that the formation was of mountains, they called it the Drakensbergen, or the "Dragons Mountain". Several possible reasons for this name include the pointy tops giving an appearance similar to that of the back of the mythical European dragon, old local myths of dragons roaming the mountains, or possible findings of dinosaur fossils. These are of course modern day assumptions.However, the word "Dragon" in Dutch and in Afrikaans is spelled "draak" and not "drak". The name for the Drakensberg Mountains comes from The Great Trek. People in the Cape Provinces who did not partake in the Great Trek called the Voortrekkers kens to carry their Ossewas over the mountains. Hence the name Drakensberge.
When most South Africans and visitors speak of the Drakensberg, they refer to the Great Escarpment that forms the border between Lesotho and KwaZulu-Natal, believing it to be a range of mountains extending into Lesotho, that more correctly is known as the Lesotho Highlands. This highest portion of the Great Escarpment is known in Zulu as uKhahlamba and as Maluti in Sotho.
Geological origins
About 180 million years ago, a mantle plume under southern Gondwana caused bulging of the continental crust in the area that would later become southern Africa. Within 10–20 million years rift valleys formed on either side of the central bulge, which became flooded to become the proto-Atlantic and proto-Indian oceans. The stepped steep walls of these rift valleys formed escarpments that surrounded the newly formed Southern African subcontinent.With the widening of the Atlantic, Indian, and Southern oceans, Southern Africa became tectonically quiescent. Earthquakes rarely occur in the region and there has been no volcanic or orogenic activity for about 50 million years. An almost uninterrupted period of erosion has continued to the present, resulting in layers several kilometers thick having been lost from the surface of the plateau. Consequently, a thick layer of marine sediment was deposited onto the continental shelf that surrounds the subcontinent.
During the past 20 million years, further massive upliftment, especially in the east, has taken place in Southern Africa. As a result, most of the plateau lies above despite the extensive erosion. The plateau is tilted such that its highest point is in the east, and it 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 where the escarpment forms part of the international border between Lesotho and the South African province of KwaZulu-Natal.
The upliftment of the central plateau over the past 20 million years and erosion resulted in the original escarpment being moved inland, creating the present-day coastal plain. The position of the present escarpment is approximately inland from the original fault lines that formed the walls of the rift valley that developed along the coast during the break-up of Gondwana. The rate of the erosion of the escarpment in the Drakensberg region is said to average per 1000 years, or per year.
Because of the extensive erosion of the plateau, which occurred throughout most of the Mesozoic and Cenozoic eras, none of its surface rocks are younger than 180 million years. The youngest rocks that remain, cap the plateau in Lesotho. These are the Clarens Formation laid down under desert conditions about 200 million years ago, topped by a thick layer of lava which erupted, and covered most of Southern Africa, and large parts of Gondwana, about 180 million years ago. These rocks form the steep sides of the Great Escarpment in this region, where its upper edge reaches an elevation in excess of.
The erosional retreat of the escarpment from the coast to its present position, means that the rocks of the coastal plain are, with very few and small exceptions, older than those that cap the top of the escarpment. Thus the rocks of the Mpumalanga Lowveld below the Mpumalanga portion of the Great Escarpment are more than 3000 million years old. In the main, the rocks of the KwaZulu-Natal Midlands belong to the Beaufort and Ecca Groups, aged 220–310 million years, and are therefore considerably older than the Drakensberg lavas that cap the escarpment on the border between KwaZulu-Natal and Lesotho.
The entire eastern portion of the Great Escarpment 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 that now forms part of the South African Low veld.
Geomorphology
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. 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 which contain tributaries of the Orange River. The large number of tributaries give the Lesotho Highlands a very rugged mountainous appearance, both from the ground and from the air.The higher parts of Drakensberg has 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 of rocks
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.Highest 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 second-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.Meanwhile, the grassy lower slopes of the Drakensberg in Swaziland, South Africa and Lesotho constitute the Drakensberg Montane Grassland, Woodland, and Forest.
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 is 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.Fauna of the high peaks
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.Fauna of the lower slopes
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, 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 '.Conservation
The high slopes are hard to reach so the environment is fairly undamaged. However, tourism in the Drakensberg is developing, with a variety of hiking trails, hotels, and resorts appearing on the slopes. Most of the higher South African parts of the range have been designated as game reserves or wilderness areas. Of these the uKhahlamba Drakensberg Park was listed by UNESCO in 2000 as a World Heritage site. The park also is in the List of Wetlands of International Importance. The Royal Natal National Park, which contains some of the higher peaks, is part of this large park complex. Adjacent to the Ukhahlamba Drakensberg World Heritage Site is the 1900 ha Allendale Mountain Reserve, which is the largest private reserve adjoining the World Heritage Site and is found in the accessible Kamberg area, the heart of the historic San painting region of the Ukhahlamba.The grassland of the lower slopes has been greatly affected by agriculture, however, especially by overgrazing. Nearly all of the original grassland and forest has disappeared and more protection is needed, although the Giant's Castle reserve is a haven for the eland and also is a breeding ground for the bearded vulture.
region
The Maloti-Drakensberg Transfrontier Conservation Area was established to preserve some of the high mountain areas of the range.