Man Shield

For the Canadian construction company, see Man-Shield.

Geological map of the Tarkwa gold district in Ghana showing significant folding and faulting

The Man Shield (Leo-Man Shield or Leo-Man Craton) is a geological shield or craton in the southeast portion of the West African Craton. The shield is in part overlaid by gold-bearing Birimian formations.

Geography and Geology

The shield covers the countries  Ivory Coast,  Mali,  Burkina Faso,  Ghana,  Sierra Leone,  Liberia, and  Guinea. ^[1]   this shield, a large portion of the WAC consists of  Paleoproterozoic   Birimian  continent margins. ^[2]

The  Birimian  units were initially produced in an immature  volcanic arc  setting, which was later metamorphosed during the  Eburnean orogeny. The poor exposure of the  greenstone belt  in the area limits interpretations of a broad structural context. The limited  greenstone belt  exposure indicates a major  deformation  event associated with  granitoid   intrusions. ^[3] The shield hosts world-class gold deposits, important  iron ore  concentrations, and the  mineralization  of aluminum ore, lead-zinc,  manganese,  phosphate, and  uranium. A majority of the gold deposit formations occurred during the  Eburnean orogeny, but a number of the remaining gold deposits formed before this orogeny during a period of oceanic arc-back-arc basin  formation and  erosion  during the  Neoproterozoic  and  Cretaceous. ^[4]

See also

• Geology of Ghana

References

1. Jessell M.W., Liégeois J-P. (2015). "100 years of research on the West African Craton". Journal of African Earth Sciences. 112(B): 377– 381.  doi : 10.1016/j.jafrearsci.2015.10.008
2. Ennih N. & Liégeois J-P. (2008). The Boundaries of the West African Craton. Geological Society, London, Special Publications. 297: 1–17.  doi : 10.1144/SP297.1
3. Ganne J., De Andrade V., Weinberg R.F., Vidal O., Dubacq B., Kagambega N., Naba S., Baratoux L., Jessell M., Allibon J. (2011). "Modern-style plate subduction preserved in the Palaeoproterozoic West African craton". Nature: Geoscience. 5: 60-65. doi : 10.1038/ngeo1321
4. Markwitz V., Hein K.A.A., Jessell M.W., Miller J. (2016).M "etallogenic portfolio of the West African craton". Ore Geology Reviews. 78: 558-563.  https://doi.org/10.1016/j.oregeorev.2015.10.024

External links

• Mason, Robert, ed. (1992), Basement tectonics 7 : proceedings of the Seventh International Conference on Basement Tectonics, held in Kingston, Ontario, Canada, August 1987, Dordrecht: Kluwer Academic, ISBN   0-7923-1582-0
• Virginia Heffernan (August 2008), Exploring in Africa, Earth Explorer, archived from the original on 2020-06-09, retrieved 2009-03-25
• Haggerty, S. E., Hills, D. V., & Toft, P. B. (1987-07-13), "Crustal Evolution and the Eclogite to Granulite Phase Transition in Xenoliths from the West African Craton", Workshop on the Growth of Continental Crust, University of Massachusetts: 68, Bibcode:1988gocc.work...68H
• Imrich Kusnir (1999), "Gold in Mali" (PDF), Acta Montanistica Slovaca, 4: 311–318, retrieved 2009-03-25
• Thomas Schlüter (2006-01-16), Geological Atlas of Africa: Liberia, Springer Berlin Heidelberg, doi:10.1007/3-540-29145-8_31
• WAXI: West African Exploration Initiative, West Africa Exploration Initiative, archived from the original on 2011-07-22, retrieved 2009-03-25
• West Africa Exploration Initiative: Stage 1 (PDF), AMIRA International Limited, June 2006, retrieved 2009-03-25^{[ permanent dead link ‍]}
• E.I. Nikolenko; V.P. Afanasiev (2008), Magnetic picroilmenites from Guinean (Africa) and Yakutian kimberlites (PDF), Russian Academy of Sciences, retrieved 2009-03-25
• Regional geology of West Africa, Minerals Commission (Ghana), retrieved 2009-03-25