Wednesday, February 7, 2018

Advancing Dunes

About two weeks back I had to make a trip down to Kenton-on-Sea in the Eastern Cape.  Now we have been going to Kenton since I was just a nipper as I have an uncle who has lived there since time immemorial.  He is nearly as old as the rocks that outcrop along the shoreline, or so it seems to me.  Anyway, I mustn't digress.  That portion of the coast is not only beautiful but full of interesting geology - two rivers stretch inland for many miles, with Kenton almost marooned between the two - it was in its day almost an island before they built the two bridges across the Bushman's River on the western side.  Vertical sediments of the Cape Fold Belt outcrop along the Kariega River, fossilised sand dunes stand sentinel along the coats,  one of which forms one of Kenton's famouse landmarks,  Carriage Rock, because it looks like an old carriage.

But it is the modern sand dunes that I want to talk about today.  They stretch for miles along that Eastern Cape coast, unsullied by developments or human activity.  At Woody Cape, on the northeastern corner of the Addo Elephant Park there is a huge dunefield called the Alexandria Dune Sea which forms part of a larger dune system the details of which are not to be discussed here.

What I did want to illustrate was how these dunes migrated ahead of the prevailing winds and I took a short video which shows the aeolian (wind blown) sands being driven up the windard (stoss side) of the dune and jetted into open space, where they settle as foresets on the lee side.  Ongoing wind action will cause the dunes to migrate downwind over time, enveloping all that stands in their way. 

Check out the video below.

https://www.facebook.com/gerald.davie/videos/10216405998769064/

Friday, July 15, 2016

Marmaduke the Tyrannosaurus Rex, and the DinoZone

Well, there has been some palaeontology activity in  Hilton, South Africa thanks to the arrival of Marmaduke the Tyrannosaur rex.  Six metres of ornery crittr now occupies pride of place in the GeoZone Hilton office and he has been quite a hit with the kids, and the parents too for that matter.  He even made it onto the front page of the local broadsheet and on national television.  Fame at long last.  For those who may be interested he has his own Facebook page here, and is featured on the DinoZone website here, and for more on dinosaurs with a South African flavour go here.

A pic to whet your appetite below:



Sunday, January 23, 2011

GeoZone Photographic Competition

GeoZone GeoServices is running an inaugural photographic competition and is open to anyone with an interest in the geotechnical and engineering disciplines. We therefore invite everyone to send in their best images of any geological, mining, geotechnical or engineering subject. With any luck this will become an annual event and we can attract some good prize money and increase the number of categories.

Roger and Pat de la Harpe of Africa Imagery fame will be judging the competition, and should their image be selected as a potential winner it may well be included in the Africa Imagery image bank. If Africa Imagery sells on the image a royalty fee will be paid out use of the image. So send in those great images and with any luck, you might grab the prize money.

Please send images of no more than 1 MB to geologist@netactive.co.za. Should your images be shortlisted we will require larger files and if possible the RAW images. Please download the competition application form at http://www.geozone.co.za/GeoZone_Geotechnical_Photography_Competition.htm.

Happy snapping, and may we take the opportunity to wish you the best of luck.

Rules:
* Closing date for entries is 30 April 2011
* The results will be announced on 15 May 2011
* The judges decision is final and no negotiation will be entered into with regard to the prizes.
* By entering your agree to incorporation of your images into the Africa Imagery image bank and allow GeoZone GeoServices to post your images onto the GeoZone site.

Wednesday, January 5, 2011

Dinosaur Footprints in Lesotho



We were in Lesotho just before the new year, mostly to get away from the usual humdrum of suburban life, but also to take in magnificent mountain scenery, geology, the spectacular Maletsunyane Falls, and look for dinosaur footprints. We met with success in all departments, and had a laugh too. The Land Rover behaved itself - in fact went like a dream up those impossibly long, steep mountain passes which was a relief to say the least. I had given her a stern talking to a few months back - any more breakdowns and trouble from you and you are out on your ear - new owners, perhaps even the scrap yard for you if you don't buck up your ideas. So she seems to have taken note and with any luck the truculence of the last 18 months has come to an end. But on to more serious things - mostly dinosaur footprints. With a bit of help from the Lonely Planet guide, the GPS, and the local Basotho lads we found the most magnificent dinosaur footprints under a rock overhang. It is perhaps a bit of an indictment on the geological community that one has to find out information on such significant things as dinosaur fossil tracks from an Australian published travel guide. Well done to Lonely Planet, Nil points to the geologists. But now we hope to rectify this, so if you want to go see them, here are the co-ordinates: S28 54.151 E27 59.864 or if you prefer: S28.90252 E27.99774 or S28 54 09.1 E27 59 51.9.

They must be at least 10 metres up and under the overhang, and the ones at the entrance to the cave are closer and more impressive. That said, they are very well preserved and it looks as if there was a whole herd of them galloping around in the sediments. We are considering ways of jugging up and taking casts at the moment - will need to revisit my rope access skills.

Wednesday, April 15, 2009

After a couple of technical glitches and a shed load of hard work www.geozone.co.za went live. We have taken a two pronged approach, so if you are interested in geotechnical issues, please follow the links through to the relevant portion of the site. Otherwise click through on the Romancing the Stone image and come explore the world of geology with us. www.geozoneonline.com. For information on our workshops and safaris go to www.oldcanvasexpeditions.com.

Saturday, April 4, 2009



www.oldcanvasexpeditions.com

We had a very succesful trip about a month ago when we journeyed with Roger and Pat de la Harpe to Bonamanzi Game Reserve, and then through to Clarens to scout out venues for various workshops. Bonamanzi is located right on the shores of Lake St Lucia and the World Heritage Site of Isimangaliso forms their northern boundary, so they are perfectly positioned in terms of birding, photographic and drawing and painting safaris. The views out of what is the largest wetland in Africa are phenomenal, and then there are the delights of the reserve itself. Accommodation comprises delightful, air conditioned thatched chalets, all with en-suite bathrooms, set in beautiful, thorn tree studded parkland with warthog and nyala wandering freely through the camp. Some of the classes will be held in a beautiful, semi-enclosed deck overlooking an African waterhole where the water lilies splash their colour across the languid waters and frogs serenade one another late into the night.



Dinners are served beneath the star-studded heavens, where cathedrals of candles and a huge camp fire throw flickering, golden shadows across enchanted faces. Delicious food, chilled drinks and convivial company are a given, and time is marked by the slow wheel of the Southern Cross through the African sky.

We reluctantly left Bonamanzi and headed inland to the second highest town in South Africa - Clarens. Again a very successful couple of days, for we found dinosaur remains, explored the Golden Gate National Park from a geological point of view and looked into the possibility of taking participants over the highest road in Africa to the Letseng Diamond Mine. Letseng is the highest diamond mine on Earth and has produced four of the twenty largest diamonds ever discovered.

We approached the mine to ask them if they would take tours and they have agreed to do this, so this is a huge feather in Old Canvas Expeditions' cap, and an exciting addition to our workshop. We have also organised flights along the Eastern Escarpment to take in the second highest waterfall in Earth - the Tugela Falls - the towering buttresses of the Drakensberg/uKhahlamba World Heritage Site, and the vast Post Gondwana Landscape which stretches out to the east.

Certainly experiences not to be missed and we would urge everyone to come on one of our safaris. As we say, more than just a game drive. Go to www.oldcanvasexpeditions.com for more information.