February 9, 2018
Last week I shared the above picture of the Oorlogskloof Glacial Pavement for my “Monday Geology Picture” series.
Today I’d like to share some more pictures and also a little more information about this incredible geologic site.
Oorlogskloof is the name of the farm where the glacial pavement is located. The name is Afrikaans and translates as “War Valley”. Oorlogskloof is located about 4 hours drive north of Cape Town, South Africa, near the town of Nieuwoudtville.
The glacial pavement is about 300 m wide and 140 m long. On the pavement, you can see impressive glacial grooves that were carved by Dwyka glaciers 300 million years ago. A fence protects the site, which is a short distance off the road. A nice information sign has been put up, with explanation both in Afrikaans and in English. There is even a road sign that reads “Glacial Pavement” – now that’s not a road sign that you see every day!
In addition to the information sign, the South African Council for Geoscience has prepared a wonderful guide to the site. You can download it here.
An excerpt from the guide is:
About 300 million years ago, glacial conditions
prevailed over Southern Africa when it migrated with
the rest of the Gondwana supercontinent over the
South Pole. The ridges and striations in the sandstone
at Oorlogskloof formed as a result of ice movement
during this time.
The grooves were not made on bedrock, but in a thin
layer of sandy debris trapped between bedrock and
the glacier base. This veneer of glacial detritus, which
was eroded from sandstone bedrock and carried
along by the ice, is preserved as a pebbly quartzose
sandstone. The grooves were made by rock and
pebbles held in the ice.
Please go and read the rest of this excellent guide.
Here are some more pictures of the spectacular glacial grooves:
If you find yourself in South Africa, I highly recommend a visit to the glacial pavement. It’s worth the 4 hour drive from Cape Town, and you’ll see some spectacular geology on the way as you drive through the Cape Fold Belt. The general scenery in the area is also very beautiful.