I want to know more about ore deposits in ophiolites.
Dear Gholamreza Fotoohi Rad ,
Here is very good article, like a direct response to your question:
Do you think can be any mineral deposits in ophiolitic Plagiogranites?
Article Origin and Heavy Metals of Plagio-Granites in Egyptian Shiel...
Many things are possible, but it would be good to know the environment in question directly.
Regards,
Laszlo
Dear Gholamreza: those deposits in Egypt are in the Nubian Shield, therefore they must be plagiogranites from a TTG Suite, in a TTG-GSB terrane, not ophiolitic ones! The only deposits the ophiolitic plagiogranites or thondhjemites could have is themselves, as they represent a good source of sodium-rich plagioclase very useful in the ceramic and related industries. Regards, Sebastian
It would be nice to see the next paper:
Article Chemical variations of mineral inclusions in Neoproterozoic ...
(its first map)
and the description of in its geological settings:
It is begin with the next:
'2. Geological setting The study areas, located in the Southern Eastern Desert of Egypt (Fig. 1a, b), represent a part of the Neoproterozoic ophiolites of the Arabian–Nubian Shield (ANS) in the NE Pan-African belt (Ghoneim et al., 2002). The main rock units around Wadi Arais (Fig. 1a) are tectonically arranged based on their field relationships into: Bitan gneisses, Balamhindit and Arais mafic–ultramafic rocks (Dismembered-ophiolite), Umm Araka metavolcanics (Island Arc-assemblage), volcaniclastic metasediments (Arais mѐlange), younger granites and Phanerozoic sediment (Ghoneim et al., 2002). The island-arc volcanics (=Umm Araka metavolcanics) consist mainly of meta-andesite, metadacite and minor metabasalt (Ghoneim et al., 2002). The three large ophiolitic complexes in the investigated areas are named: Balamhindit, Arais, and Abu Dahr (Fig. 1a, b). The chromitite pods vary in size and shape, and are outcropped in these three complexes; many of them have already been worked out by (...)
And try to find the place of (Abu Dabbab Area (see the attched file)
Neither you nor I know the area very well. Therefore, we should be careful what we say. I was wrong too, because I looked at it superficially. But I was lucky that my geological intuition was good, because the area Abu Dabbab Area is close to Read Sea) You used a theoretical scheme, which in many cases leads to false conclusions if you don't check it.
You are a professor, therefore you are bound by the material you teach.
I don't have that problem. I understand geology the way I feel it's good, I don't have to fear that I'll be fired from my job if I don't say what I'm told from above.
Regards,
Laszlo
Metals? Nothing seems to pop up. Emeralds? Interesting possibility for such a huge area as the Egyptian occurrence. Plagiogranites in the large Egyptian massive are reportedly recycled crust and as such should contain lithophile elements...Be etc. Typically Be systems follow two mica granites etc. and the presence of "evaporitic" and carbon bearing schistose material seem important but Plagiogranites? Hm... Tourmaline pods in the plagiogranite suggests Be. The adjacent Opholites seem like decent chromium sources. The contact zone or throughgoing faults...maybe. It seems like a long shot...but... There are reports of emeralds found in the Eastern Egyptian deserts which I am sure many are familiar with. This lengthy report is a bit old but seems very interesting. It does review Eastern Egyptian emerald mineral occurrences.
Hope this opens up properly.
Minerals | Free Full-Text | Emerald Deposits: A Review and Enhanced Classification (mdpi.com)
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