Cape Peninsula

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The Cape of Good Hope; looking towards the west, from the coastal cliffs above Cape Point.
Map showing the Cape Peninsula, illustrating the positions of the Cape of Good Hope, Cape Point and Cape Town.
Map showing the locations of the Cape of Good Hope and Cape Agulhas.

The Cape Peninsula (Afrikaans: Kaapse Skiereiland) is a generally rocky peninsula that juts out into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Cape of Good Hope. On the northern end is Table Mountain, overlooking Cape Town, South Africa. The peninsula is 52 km long from Mouille point in the north to Cape Point in the south.[1]

The peninsula was once an island, but about sixty million years ago it was joined to the mainland by the emergence from the sea of the sandy area now known as the Cape Flats. The towns and villages of the Cape Peninsula now form part of the City of Cape Town Metropolitan Municipality.

The Cape of Good Hope is sometimes given as the meeting point of the Atlantic Ocean and Indian Ocean, and the west coast of the Peninsula is colloquially referred to as the "Atlantic Coast",[2] with the western (False Bay) side sometimes referred to as the "Indian Ocean Coast".[dubious ] However, according to the International Hydrographic Organization agreement that defines the ocean boundaries, the meeting point is at Cape Agulhas, about 200 km (120 mi) to the southeast.[3] [4]

Similarly, Cape Point is not the fixed meeting point of the Benguela Current, running north from the Antarctic and up the west coast of Africa, and the Agulhas Current, running south from the equator along the east coast of Africa. The meeting point fluctuates along the southern and southwestern Cape coast, usually occurring between Cape Agulhas and Cape Point.

Ecology[edit]

Bioregions of SA EEZ

Table Mountain National Park, previously known as the Cape Peninsula National Park, proclaimed on 29 May 1998, for the purpose of protecting the natural environment of the Table Mountain Chain, and in particular the rare fynbos vegetation. The park comprises a large part of the undeveloped area of the Cape Peninsula, and is managed by South African National Parks Board. The coastal waters surrounding the Cape Peninsula are proclaimed as a Marine Protected Area since 2004, and include several no-take zones, and are part of the National Park. The waters of this marine protected area are unusual in that they are parts of two fairly distinct marine bioregions, namely the Agulhas Bioregion and the South-western Cape Bioregion. The boundary is at Cape Point.

The park contains two well-known landmarks: Table Mountain, for which the park is named; and the Cape of Good Hope, the most southwestern extremity of Africa.

Geology[edit]

Sea Point contact zone mixed rocks

The Cape Peninsula is underlain by the oldest rocks in the area, the Malmesbury Group, and the granite intrusions of the Peninsula pluton.

The Malmesbury Group has been dated from between 830 and 980 Mya, and was deformed during the Saldanian orogenic cycle, both before and during the granite intrusions of 630 to 500 Mya, and there are minor intrusions which precede the granite. The base of this group has not been exposed.[5] The basal rocks were eroded to a relatively featureless peneplain with exposed granites covering most of the peninsula south of Lion's Head and Devil's Peak. The Sea-Point contact zone, described by Charles Darwin is a well known region of metamorphic rocks formed by the granite intrusion into the Malmesbury rocks.

These rocks were later unconformably covered by the Cape Supergroup. The Cape Supergroup is divided into eight formations, the three oldest of which are present on the Peninsula. The lowest present is the reddish Graafwater formation which consist of shales and sandstone. This is overlain by the prominent Table Mountain Group, which consist mainly of hard, erosion resistant, quartzitic sandstone, which form the high, prominent, almost vertical cliffs of the Cape Peninsula. At the very top of Table Mountain, at Maclear's Beacon, is a small remnant of the Pakhuis Diamictites, better represented in the Cederberg Mountains, 200 km to the north of Cape Town .[5]

References[edit]

  1. ^ 1:250,000 Geological Series map 3318:Cape Town, Government Printer, Pretoria, 1990.
  2. ^ http://www.discoverthecape.com/atlantic-coast.html
  3. ^ http://ioc.unesco.org/oceanteacher/OceanTeacher2/01_GlobOcToday/03_GeopolOc/s23_1953.pdf
  4. ^ http://www.southafrica.info/about/geography/oceansmeet.htm
  5. ^ a b Theron, J.N. Gresse, P.G. Siegfried, H.P. and Rogers, J. Explanation sheet 3318 – The Geology of the Cape Town Area. Geological Survey, Department of Mineral and Energy Affairs, Government Printer, Pretoria 1992. ISBN 978-0-621-14284-6

Coordinates: 34°12′18″S 18°24′14″E / 34.205°S 18.404°E / -34.205; 18.404