The Pilanesberg (formerly Pilandsberg) is a mountain in the

North West Province North West is a province of South Africa. Its capital is Mahikeng. The province is located to the west of the major population centre of Gauteng and south of Botswana. History North West was incorporated after the end of Apartheid in 1994, an ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. The mountain is an ancient volcanic structure, circular in shape, that rises from flat surrounding plains. It is formed by three concentric ridges or rings of hills, of which the outermost has a diameter of about 24 km. The Pilanesberg is located 100 km to the North-West of

Pretoria Pretoria () is South Africa's administrative capital, serving as the seat of the Executive (government), executive branch of government, and as the host to all foreign embassies to South Africa. Pretoria straddles the Apies River and extends ...

and is for the greater part enclosed in a

protected area Protected areas or conservation areas are locations which receive protection because of their recognized natural, ecological or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the ena ...

known as

Pilanesberg National Park The Pilanesberg National Park is located north of Rustenburg in the North West Province of South Africa. The park borders on the Sun City entertainment complex. It is currently administered by the North West Parks and Tourism Board. The area ...

. The Elands River flows South of the Pilanesberg in an Easterly direction. There are a number of

platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinu ...

mines right at the perimeter of the crater formation. The name "Pilanes" comes from a historic

Tswana Tswana may refer to: * Tswana people, the Bantu speaking people in Botswana, South Africa, Namibia, Zimbabwe, Zambia, and other Southern Africa regions * Tswana language, the language spoken by the (Ba)Tswana people * Bophuthatswana, the former ba ...

chief named Pilane.

Geology

Although geographically located within the

Witwatersrand The Witwatersrand () (locally the Rand or, less commonly, the Reef) is a , north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, which ...

range, the mountain is

geologically Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other E ...

part of a feature known as the ''Pilanesberg Alkaline Ring Complex''. It is a vast

ring dike A ring dike or ring dyke is an intrusive igneous body that is circular, oval or arcuate in plan and has steep contacts. While the widths of ring dikes differ, they can be up to several thousand meters. The most commonly accepted method of ring dik ...

of a very ancient extinct

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

that last erupted some 1,200 million years ago. The Pilanesberg is one of the largest volcanic complexes of its type; there are few similar alkaline volcanic structures in the world. Different types of

syenite Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). Some syenites contain larger proport ...

s, including a number of rare minerals, occur in the crater area.Mindat - Pilanesberg Mt
/ref> The formation of the Pilanesberg occurred 2 billion years ago. As its zenith, the volcano towered to 7,000 metres in height. Over the time, a series of volcanic eruptions occurred. There were further outpourings of lava, craters collapsed, ring fracturing took place around the volcano and magma was squeezed into these fractures. The result is several "onion rings" of rocks of different ages. Erosion over many millions of years has stripped away the mountain and the highest peak. What we see today is not so much a volcanic crater, but a cross section through the magma pipes that were located at great depth below the mountain's summit.

References

External links

NASA Earth Observatory hi-res photos and article, 22 July 2015Travel Guide and Information. Interactive 3 D Map and Photographs of the Pilanesberg National ParkThe Pilanesberg Game Reserve Travel & Safari Guide
Landforms of North West (South African province) Mountains of South Africa Proterozoic calderas Volcanoes of South Africa {{NorthWestZA-geo-stub

Geology

See also

References

External links