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
editThe 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
editReferences
edit- ^ 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
- ^ 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
- ^ 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
- ^ 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
edit- 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
{{citation}}: CS1 maint: multiple names: authors list (link) - 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
- 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
 | This palaeogeography article is a stub. You can help Wikipedia by expanding it. |