Michel:

Kindly see this link for insights:

http://www.the-eis.com/data/literature/Granite%20Landforms%20of%20the%20Central%20Namib_2000.pdf

Best

Syed

Syed,

Many thanks. I am working on a geological guidebook of Namibia. Your paper will definitely help.

Cheers.

Michel

Hi Michel,

The granitoid intrusives at Wüstenquel to which you refer have yet to be subject to (published) radiometric dating, and as far as I know, are unnamed. However, regional mapping of the central and southern Damara mobile belt by several authors suggests that they belong to the suite of syn-tectonic intrusives of the so-called Salem-type (Miller 1973), characteristic of the central part of the mobile belt.

By contrast, the Donkerhoek Granite (granodiorite) situated in the southern belt, and largely intruded to the south of the important Okahandja  Lineament, is generally regarded as a post-tectonic intrusive suite.

The Age of the Donkerhoek Granite is given variously as 522ma (Haack, 1982) to 527ma, whereas the Salem-type intrusives span a wide range of reported ages from 560ma to 480ma (op. cit.).

Also the two suites appear to be geochemically distinct, with an entirely ensialic S-type source invoked for the Salem intrusives, contrasting with a mixed crustal and mantle source in the case of the Donkerhoek granodiorite (Martin, 1983).

The nearest well-studied (and dated) Salem-type intrusives to those at Wüstenquel is the Stinkbank Granite to the northeast. Johnson et. al. (2006) report a U-Pb zircon LAM-ICP-MS age of 549 ± 11ma which they assert “represents the first robust age  for the crystallization of a member of the regionally widespread suite of syntectonic  Salem-type granites”

I have produced a couple of overlays of a geological map showing the relevant intrusive age relations, taken from Owen (2011) (after Miller, (2008)), which I have registered to the underlying satellite imagery. The first allows tracking of the underlying geology, the second maximises the legibility of the key.

Hope this helps

Regards

Graham    

Haack, U., J. Hoefs, and E. Gohn. "Constraints on the origin of Damaran granites by Rb/Sr and δ18O data." Contributions to Mineralogy and Petrology79.3 (1982): 279-289.

Johnson, Shannon D., Marc Poujol, and Alexander FM Kisters. "Constraining the timing and migration of collisional tectonics in the Damara Belt, Namibia: U-Pb zircon ages for the syntectonic Salem-type Stinkbank granite." South African Journal of Geology 109.4 (2006): 611-624.

Martin, Henno, and Franz Wolfgang Eder, eds. “Intracontinental fold belts: case studies in the Variscan Belt of Europe and the Damara Belt in Namibia”. Springer Science, 1983

Miller, R. "McG: The Salem granite suite: genesis by means of partial melting of the Khomas schist." Geol. Surv. S. Afr., Mem 64 (1973).

Miller, R. McG. (2008). “The Geology of Namibia: Neoproterozoic to lower Paleozoic”. Minestry of Mines and Energy Geological Survey, vol 2

Owen, Geoffrey J. “Geology of the Kranzberg syncline and emplacement controls of the Usakos pegmatite field, Damara belt, Central Namibia”. Dissertation, University of Stellenbosch, 2011.

Graham,

Many thanks. That's the perfect answer.

I was not sure it was part of the Donkerhoek Granite as they are more east. I was trying to get the Miller, R. McG. (2008). “The Geology of Namibia: Neoproterozoic to lower Paleozoic” but it is almost impossible to find. I wrote emails to some bookshop in Windhoek but never got any answer. I just have the Schneider G. (2008) and the Grünert N., (2013) which are too simple.

A thousand thanks for your answer. I will download the papers.

Cheers.

Michel

Thanks Michel, you are very welcome. Good luck as well with your Namibia field guidebook.

Best Wishes, graham 

Good evening Michael,

I don't know if you still need information, but Miller, R. McG. (2008) is sold at the Geological Survey --> http://www.mme.gov.na/gsn/library/ We bought it several times during several field trips, and there still seem to be enough copies.

Maybe they can send you the three volumes.

Best regards,

Andreas

Hi Andreas,

Thanks for the info on the Miller's book on the Geology of Namibia.

I wrote to the Ministry of Mines and Energy but ... got no answer.

I tried again.

Cheers.

Michel