12/29/2007

Groot Kliphuis and the best campsite ever

It was still rainy when we got up the next morning but this was somewhat welcome because we planned a long uphill loop for the day. We set off north on the jeep road from De Tronk but pretty soon took off on a side trail up a steep canyon toward Groot Kliphuis.

The canyon cut across the local geology and awesomely confirmed what I thought was going on in the area. The Groot Kliphuis River runs down the center of a gently south-plunging syncline and here we are crossing out of the eastern limb. You can see the top of the Peninsula Sandstone (without Pakhuis Member?) exposed by erosion. The 'fold zone' is clearly present even if the Pakhuis Member is not. Can't tell for sure if it is there. Above the exposed sandstone surface is the grassy slope of Cederberg Shale. Atop that you can see the sandstones of the Nardouw Fm. - these are very difficult to tell from the Peninsula Fm. in outcrop but a bit more likely to make the strange and wonderful boulder piles we saw along the river.

You can see some parasitic ramp-thrust folding in the lowermost Nardouw Fm. (Goudini Mbr).

We came out on top after a steep climb into the Groot Kliphuis valley. It was really beautiful and the fynbos in early summer bloom looked almost tundra-like. One definitely can tell it gets cold up here in the winter time. The floor of the valley is a thick sandy floodplane deposit and the river running through it was the clearest and most delicious we found.

We never did find the ruins of Groot Kliphuis, unless these oak trees are it. We had a nice hot lunch here under the trees. The sun started poking through.

We lost the trail at the oak trees - or maybe we left it and went on oak-tree-autopilot? not sure. Glad we had the topo although can't say our skills were terrific, too bad I forgot my compass at home. Anyway we made it back to the trail where it winds out of the valley along the headwaters of the Groot Kliphuis River and found ourselves meandering back up stratigraphic section into the Nardouw Sandstone goblinland again:

The river drops down into a deep gorge here, we never got a clear look over the side because by this time we were 10km into our day and getting worried about finding a campsite.
We stopped to take a picture over the gorge though:

We almost camped here at this beautiful pond surrounded by orchids. It was very froggy. We were only about 5km from the parking lot at this point and we knew of one last sandy, flat site along the river so we decided to keep going to see if there was anything better. I was hot and really wanted to swim!

The trail wound away from the river for a little while and I thought I had missed my chance to cool off. The boulders got stranger and I knew we were getting near to the syncline axis where the axial planar cleavage and perpendicular jointing in the Goudini Sandstone is much stronger.
When the river hits the axis of the geologic fold, it makes a 90° turn toward the south. At this turn we found the most beautiful swimming hole, with several braided pools and little cascades between them:

We decided to camp here, figuring we were an hour or so from the car, so we could take a morning dip in the clear water and still make it out to the coast in the afternoon. Here's Sila cooking ravioli in river water:


We found a carnivorous plant! If you look closely you can see it has captured a fly in one of the curled leaves on the left:

Beautiful potholes suggest this can become a torrent during flood season:

A pebble bed in the Goudini is partially eroded to reveal steeply dipping crossbeds in the sandstone underneath. This combination of features is pretty good evidence that the sediments were deposited in a fluvial environment, although it must have been pretty huge and stark compared to todays rivers:


We camped in a sandy spot right above the swimming hole. Too Perfect for words. Spread all the wet clothes from 2 days of rain on the hot rocks and watched the sun go down over the west limb of the syncline (ridge on the horizon). Watched the myriad strange constellations come out through the mesh roof of the tent.

Sun setting over the swimming hole:

4 comments:

Trifarina said...

I wish I knew lots about geology just like you! I love the pothole, it's now my wallpaper!

Fault Rocks said...

Sweet! sadly I know of no microfossils ever recovered from the paleozoic sandstones locally

mngirl said...

Hey Christie! I found your blog thru Katie Snell's. I love the pictures from the hiking trip...I wonder if I'll ever get to do it. Sucks to know that I'll be in Pretoria for 7 months. I'm trying to find people in Botswana and Madagascar to go visit while I'm in S.A.

Genya

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