Sunday, 4 December 2011

Geological Route explored!

 It is with great excitement and delight that I am posting this blog!

Paul Rixom and two other geologists have explored Dr Chris Lee's geological route in die oervlakte book. They are raising funds for WESSA and did six different routes along the South Coast last year and are planning to add this route to their itinerary in the new year. 

This has made publishing the book absolutely worthwhile! Thank you to the geologists!

To order a book please contact 
Louise Heckl | 044 752 1143 | 083 861 8802 | exlibris@iburst.co.za



‘The Kammanassie Circuit’

A Possible Geological Tour for WESSA (Wildlife and Environmental Society of South Africa)

Inspired by the excellent publication ‘die oervlakte’ and particularly the geological route compiled by Dr. Chris Lee, myself and two friends set out on Monday 28 November from George to travel the route in order to see whether we could use it as a potential geological tour to raise funds for WESSA.

Last year we ran six geological tours for WESSA, three along the coast from Mossel Bay to Wilderness and three over the Swartberg going via Meiringspoort and returning via Prince Albert and the Swartberg Pass, all of which were a great success.

We stopped at the Village Trading Post in De Rust, where we were able to purchase a further copy of ‘die oervlakte’, and were able to chat to Niekie Eksteen who said he would be able to provide set cooked breakfasts and even packed lunches for reasonable prices for our potential WESSA group. This would make the Village Trading Post an excellent gathering and starting point for the tour.
We thought we could first take the group into Meiringspoort (geosite 14 in Chris Lee’s geological route) and talk about the folding and faulting of the Table Mountain Sandstone. We would then briefly retrace our steps and join the R341 going east. The Enon formations just north of the road could then be viewed (geosite 12 ). 




Further east along the road we could see die oervlakte on the flanks of the Kammanassie mountains to the south (geosite 11) and stop at the road cuttings in Bokkeveld shales (geosite 10).

die oervlakte

Bokkeveld shales

 
We then took the sand road north to the hot springs at Toorwater (geosite 8). It was at one time a caravan site and spa and although the site is now rather derelict we found it very interesting, particularly the large black and brown heaps of iron and manganese oxide-bearing tufa deposited from the hot springs (travertine may also describe the deposits). In some areas the tufa material was quite hard and an amazing dark blue colour, presumably related to the manganese oxide content. We immediately saw a pipe with fairly hot water gushing out into an apparent irrigation system but we were unable to trace the pipe to an ‘eye’ where we believe much hotter water comes out of the ground. We understand Chris Lee may be able to show this to us at a later date. The hot springs lie directly on a large east-west fault system that stretches from west of PE to Tulbagh. The geological map shows the Enon formation, “largely covered by alluvial slope deposits” directly faulted against the Table Mountain Sandstone to the north. We also thought that this may a reasonable picnic lunch spot for the group, although with no working toilet facilities.
Toorwater

Tufa material



We completed the sand road loop and saw Enon formations to the south (geosite 9) and the upper Olifants River valley carved out of the softer Bokkeveld shales (geosite 7). We then went east on the R341 for a short way to join the main N9 going south west. Even though we slowed down at each road cutting we were unable to see a Karoo age dolerite cutting through sandstone. Again Chris Lee might be able to help us here.
Just north of Uniondale we were impressed by the three oervlaktes (mesas) east of the road. We understand from Louise Heckl that she could arrange closer access to these features through Cobus van Rensburg of the farm Vleiplaas. It is these mesas which are illustrated in ‘die oervlakte’.

We stopped briefly in Uniondale to view the old restored watermill and had a snack at Crackling Rose’s. We understand from Louise Heckl that there are other establishments in Uniondale that could be used as a possible afternoon tea stop.
South of Uniondale we left the N9 and travelled west on the Rooikrans, Buffelsdrift, Daskop sand road. This delightful road runs south of the Kammanassie Mountains along the Kammanassie River and gives many photographic opportunities to view the many oervlaktes that are evident on the southern slopes of the main range (geosite 5). The road also follows the Bokkeveld shale, which is well exposed in several road cuttings. According to the geological map the road is in the lowest Gydo shale formation which in other parts of the Little Karoo can contain fossils such as trilobites and brachiopods. Due to time constraints we did not stop and examine the shales.




We think that ‘The Kammanassie Circuit’, which represents about a 300km round trip from George would be an excellent geological outing for WESSA sometime in the new year.

Paul Rixom