Tour Locations | Upper Cableway Station Audio Guide: Tabletop Walking Tour
NARRATOR: Now stop and look out over the mountain before you. From here, you’ll have a good view of Devil's Peak. Geologist John Rogers is an expert on its composition.
JOHN: Devil’s Peak is a good place to begin to understand the geology of the Cape Peninsula. First, we need to comprehend the age of Planet Earth, which is over four and a half billion years old. If you look at the lower half of Devil’s Peak, below the road, you'll see tightly folded, deep-marine siltstones. These are the oldest rocks in the Cape Peninsula, but they're only about 560 million years old. You'll see more of this siltstone around the Cape, some of which has been folded vertically, like the pages of a book. This is the result of the opening and then closing of the ancient Adamastor Ocean, which has long since vanished. Now look to the right of Devil’s Peak, at the gap between it and Table Mountain. This is known as the Saddle. It's a world-famous contact between the older Malmesbury Group rock and the younger Cape Granite. About 490 million years ago, the uplift and erosion of this granite and the folded siltstones enabled a river-system to deposit sandstones and mudstones at the base of the Table Mountain Group.
NARRATOR: Now backtrack until you reach the main path we’ve just turned off. Then continue to follow it as it curves away from the sea.