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Namibia Horse Safari Company

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Understanding desert landforms

Namibia’s beguiling geological features are as open books, their ‘pages’ accessible for any who care to browse.  Wether resulting from sedimentary deposits, tectonic movement or lava eruptions, each offers a glimpse into eons of geological history.


Examples of Erosional features on our safaris:




Petrified silt deposits.  


This curious erosional feature (above), now petrified into solid rock, was once a silt deposit in an ancient river. Worn by centuries of water and with the help of wind, the remaining outcrop - seen in part on the opposite bank at the same level - is a reminder that even in  a desert, water is still a major influence in changing landforms.




Granite Weathering


Granite is high in quartz - a particularly resistant rock, whereas the feldspar and mica in granite are highly susceptible to weathering processes.  When joints form - creating weak areas - salts, dissolved in fog, penetrate and dissolve the rock resulting in ‘onion skin’ exfoliation as in this image taken on our Skeleton Damara Safari.  


Another good example of granite weathering can also be seen on Bludkoppe featured on our Namib Desert Safari (below)




Lava Flows.  


Igneous Rocks.  When lava flows do not extrude (pour out) onto the surface, they intrude into pre-existing rock which subsequent erosion of softer rock surrounding the intrusion, uncovers.  The rock more resistant to weathering form inselbergs, now standing tall as proud reminders of these long processes. 


 A good example is the 2 573 metre high Brandberg mountain we pass on our way down to the coastal plains on our Damara Elephant Safari.   In the image the massive of the Brandberg can be seen as a shadowy form way beyond our mountaintop campsite on our Damara Elephant Safari. 



Interestingly, the ‘rock’ under which we camp (image above) is actually a petrified sand dune with igneous rock (laval) intrusions.  Have a closer look when next at the top of that mountain on a Damara Elephant Safari.  



Tectonic shift


The landforms in this image (above) are schist ridges which, due to folding have ‘stood up’, close to vertical from their original horizontal orientation. The schist ridges are metamorphosed sediments - meaning the layers have been modified by temperature and or pressure and then tilted due to tectonic shift


What is interesting in this picture (above) is that the stream in which our camp is set up, is the surface expression of a fault. Notice the offset of the dark units right where the truck is parked. It is shifted to the right on the other side of the stream - that could be due to tectonic shift deep underground.


Image below of Andrew negotiating the softer layers between the schist ridges.




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