Pilanesberg
| Pilanesberg | |
|---|---|
 NASA picture of Pilanesberg with Vaalkop Dam on the right side | |
| Highest point | |
| Elevation | 1,687 m (5,535 ft)[1] |
| Listing | List of mountains in South Africa |
| Coordinates | 25°14′25″S 27°4′33″E / 25.24028°S 27.07583°E |
| Geography | |
  Pilanesberg Location within South Africa | |
| Location | North West Province |
| Parent range | Witwatersrand |
| Geology | |
| Rock age | Proterozoic |
| Extinct volcano | |
The Pilanesberg (formerly Pilandsberg[2][3]) is a mountain in the North West Province, South Africa. 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 and is for the greater part enclosed in a protected area known as Pilanesberg National Park.
The Elands River flows South of the Pilanesberg in an Easterly direction. There are a number of platinum mines right at the perimeter of the crater formation.
The name "Pilanes" comes from a historic Tswana chief named Pilane.[4]
Geology
The Pilanesberg is the surface expression of the Pilanesberg Complex, a circular alkaline igneous complex covering about 625 square kilometres (241 sq mi). The complex was emplaced into rocks of the Bushveld Igneous Complex and contains coeval volcanic rocks and several distinct intrusive syenitic and foyaitic units that are arranged concentrically at the surface.[5]
Uranium–lead dating of titanite gives an emplacement age of 1,395 +10
−11 million years, during the Mesoproterozoic. The complex includes trachytes, phonolites, syenites and nepheline syenites. Preservation of part of its volcanic carapace distinguishes it from many other large alkaline complexes.[6]
The circular intrusive units were historically interpreted as a laccolith, a funnel-shaped body, or a system of ring dikes and cone sheets. Cawthorn argued that the principal coarse-grained bodies, which exceed 1 kilometre (0.62 mi) in radial width, are too wide and coarse-grained to be conventional ring dikes or cone sheets. Poor exposure makes the three-dimensional relationships among the intrusive units difficult to determine directly.[5]
See also
References
- ↑ Impati
- ↑ Humphrey, W.A. (1914). The Geology of the Pilandsberg and the Surrounding Country: An Explanation of Sheet 12 (Pilandsberg). Pretoria: Geological Survey, Department of Mines. p. 32.
- ↑ Kynaston, H., Humphrey, W.A. (1920). The Geology of the Northern Portions of the Districts of Marico and Rustenburg. Pretoria: Geological Survey, Department of Mines and Industries.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ↑ Raper, R.E. Dictionary of Southern African Place Names. Human Sciences Research Council (South Africa).
- 1 2 Cawthorn, R. Grant (2015). "The geometry and emplacement of the Pilanesberg Complex, South Africa". Geological Magazine. 152 (5): 802–812. doi:10.1017/S0016756814000764.
- ↑ Elburg, Marlina A.; Cawthorn, R. Grant (2017). "Source and evolution of the alkaline Pilanesberg Complex, South Africa". Chemical Geology. 455: 148–165. doi:10.1016/j.chemgeo.2016.10.007.
External links
- NASA Earth Observatory hi-res photos and article, 22 July 2015
- Travel Guide and Information. Interactive 3 D Map and Photographs of the Pilanesberg National Park
- The Pilanesberg Game Reserve Travel & Safari Guide
- Platmin Platinum Mine, Pilanesberg, South Africa Archived 23 July 2009 at the Wayback Machine
- Platmin halts work at Pilanesberg Archived 28 September 2011 at the Wayback Machine