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Thursday, August 11, 2011

Table Mountain

Table Mountain is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa, and is featured in the flag of Cape Town and other local government insignia. It is a significant tourist attraction, with many visitors using the cableway or hiking to the top. The mountain forms part of the Table Mountain National Park.

Features

The main feature of Table Mountain is the level plateau approximately 3 kilometres (2 mi) from side to side, edged by impressive cliffs. The plateau, flanked by Devil's Peak to the east and by Lion's Head to the west, forms a dramatic backdrop to Cape Town. This broad sweep of mountainous heights, together with Signal Hill, forms the natural amphitheatre of the City Bowl and Table Bay harbour. The highest point on Table Mountain is towards the eastern end of the plateau and is marked by Maclear's Beacon, a stone cairn built in 1865 by Sir Thomas Maclear for trigonometrical survey. It is 1,086 metres (3,563 ft) above sea level, about 19 metres (62 ft) higher than the cable station at the western end of the plateau.

The cliffs of the main plateau are split by Platteklip Gorge ("Flat Stone Gorge"), which provides an easy and direct ascent to the summit and was the route taken by António de Saldanha on the first recorded ascent of the mountain in 1503.

The flat top of the mountain is often covered by orographic clouds, formed when a south-easterly wind is directed up the mountain's slopes into colder air, where the moisture condenses to form the so-called "table cloth" of cloud. Legend attributes this phenomenon to a smoking contest between the Devil and a local pirate called Van Hunks. When the table cloth is seen, it symbolizes the contest.

Table Mountain is at the northern end of a sandstone mountain range that forms the spine of the Cape Peninsula. To the south of the main plateau is a lower part of the range called the Back Table. On the Atlantic coast of the peninsula, the range is known as the Twelve Apostles. The range continues southwards to Cape Point.


Geology

The upper part of the mountain mesa consists of Ordovician quartzitic sandstone, commonly referred to as Table Mountain Sandstone (TMS), which is highly resistant to erosion and forms characteristic steep grey crags. Below the sandstone is a layer of micaceous basal shale, which weathers quite readily and is therefore not well exposed. The basement consists of heavily folded and altered phyllites and hornfelses known informally as the Malmesbury shale. This has been intruded by the Cape Granite. Both rocks are of late Precambrian age. The basement rocks are not nearly as resistant to weathering as the TMS but significant outcrops of the Cape Granite are visible on the western side of Lion's Head.



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