Rock of ages

Mountains are often thought of as timeless; unchanged by the passage of time, impervious to the ravages of the elements. But the reality is they age as much as we do, just on a much slower scale.

Table Mountain is no exception. Time is fast running out for this crumbling relic of a mountain. Composed largely of sandstone deposited 540 million years ago by large rivers and inland seas, the mountain first came into being when the supercontinent of Pangaea scrunched into an unknown continent about 360 million years ago, uplifting the sedimentary rock around the Cape in a concertina-like formation that reached heights of about 3000 meters. Back then, Table Mountain formed part of a much larger mountain range, and it would take 300 million years of erosion to reduce it to its current shape and size. So the mountain as we see it today, with its distinctive tabletop, is only about 60 million years old – still a venerable age compared to that of the Alps (32 million years) and the Himalayas (40 million years), and bearing in mind the age of the rock itself (540 million years).

Table Mountain is actively eroding. Proof of this can be found on any hike up the mountain, where boulders the size of houses can be seen perched precariously on cliffside ledges. Another 10 million years or so will see Table Mountain reduced to an inconspicuous hillock. Wind and rain combine to wear away the sandstone layers. Expansion cracks form as the mountain sheds weight, aiding the erosive action of the elements. On a human scale, with 70 taken as the average life-expectancy, Table Mountain (in its current shape and size) has attained the ripe age of 60. Still 142 857 human lifetimes to go.

There is no better way to acquaint yourself with the geology of Table Mountain than on foot. Join Hike Table Mountain on a hike to discover some of the mountain’s weird rock-formations, caves and striking topographical features.

Forthcoming blog: ‘Why is Table Mountain flat?’

(c) www.hiketablemountain.co.za

Happy 2012 to all. Make it count. Make it happen. Make time to connect with nature.