The coordinates will take you to a magnificent viewpoint of the Oribi Gorge. The Umzikulwana River has cut this dramatic Oribi Gorge into the rock plateau. It is one of the most spectacular gorges in Southern Africa and is some 24 kilometres long and 400 metres deep.
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Logging Tasks:
1) At the listed coordinates you will also see a pinnacle of rock about 100 metres in front of you. Describe this formation in terms of layers, colours and rock formation/shape.
2) Estimate the height of the pinnacle.
3) What classification of rocks forms the cliffs of the gorge?
4) What erosion processes do you think formed this gorge?
5) What inscription is on the sign at coordinates S30 40.224 E030 18.189?
Geology:
The basement rocks were formed approximately 1000 million years ago. Subduction and collision along the southern margin of the Kaapvaal Craton produced the rocks of the Natal Metamorphic Province. The rocks were heated and deformed into a mountain range. Once plate collision with the Kaapvaal Craton had ceased a long period of erosion exposed the mountain roots of granite and gneiss.
Subsequent to this the first sedimentary sequence, known as the Natal Group Sandstone, was deposited on the basement during the Cambrian to Ordovician period, which occurred some 490 million years ago.
Structures preserved in these sandstones indicate that the sediments were transported and deposited by rivers that drained highlands to the northeast. The sediment deposited here in the south was finer grained than the north and forms the resistant sandstone cliffs of the spectacular Oribi Gorge.
Sources:
geology ukzn