How Table Mountain got its iconic shape

How Table Mountain got its iconic shape

image Table Mountain's iconic shape. Photo courtesy Caroline Mitchell

Although Table Mountain appears to be flat on top when viewed from the city way below, when you’re actually standing on it, you’ll be surprised to discover that the three-kilometre-long plateau is actually not that flat at all.

The mountain – estimated to be 260-million years old – has retained its table-like appearance due to the composition of its upper cliffs, which are made of resistant Table Mountain Sandstone (TMS). TMS is formed over millennia by river-borne sediment that has compacted under its own weight and turned to stone.

Around 450-million years ago sandstone was deposited on the tidal flats that blanketed the region. The sand, silt and mud deposits were transformed into stone by pressure before being folded back along the southern coast.

Road cuttings on the slopes of Table Mountain reveal layers of pale brown sandstone, laminated pink siltstone and dark maroon-coloured shale, showing the ebb and flow of former flood plains and lagoons.

You can see similar layers by taking a scenic trip along Chapman’s Peak Drive. The roadway has been constructed at the meeting point of a granite underlay and the upper sandstone layer.

Today’s landscape all the way from the Cape Flats, with its characteristic deep valleys, has been sculpted by prolonged erosion that has degraded the TMS covering, leaving behind residual mountain ridges.

At the highest points on the tabletop, a glacial gravel (Pakhuis Formation tillite) can be found. These boulders and pebbles, found at Maclear’s Beacon, were deposited at a time when the world was still a single continent.

Table Mountain’s top is flanked by Devil’s Peak to the east and Lion’s Head to the west. The mountain creates a natural backdrop to the Mother City, and, when combined with Signal Hill, forms an amphitheatre overlooking the City Bowl.

Remember that you can buy return Cableway tickets online and skip the Ticket Office queue.

See also:

•    Table Mountain: more than just a pretty face

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