Earth:Darfur Dome

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The Darfur Volcanic Province from ISS.

Darfur Dome or Darfur Volcanic Province is an area of about 100x400 km in Western Sudan. As well as its best-known and central feature, Deriba Crater, it encompasses the surrounding Marra Mountains (Jebel Marra) and Tagabo Hills, both formed around 16–10 Ma, and the Meidob Hills, formed around 6.8 Ma.[1]

There are currently two competing theories concerning Darfur Dome’s formation. The conventional view is that magmatism is the product of a rising mantle plume, with active volcanism being triggered by stress resolution along the Central African Fault Zone.[1][2] Evidence for a plume origin includes domal uplift, gravity anomalies, and low seismic velocity zones in the mantle,[1][2][3][4][5][6] though there is disagreement over whether these indicate a discreet, narrow plume under the Darfur region[1][2][3] or a broad superplume with conduits feeding several African hotspots.[4][5][6]

Recently, some scientists have argued for a tectonic origin in which lithospheric extension, asthenospheric shear, and small-scale convection have enabled passive melting of shallow source material.[7][8][9][10] This interpretation is supported by high seismic shear wave velocities which indicate shallow, cold downwellings[7] as well as normal heat-flow and low helium isotope ratios.[8][9]

  • Deriba Caldera

  • Jebel Marra Deriba Lakes

  • Central Africa showing CASZ.

Notes

  1. ↑ 1.0 1.1 1.2 1.3 Franz, G.; Pudlo, D.; Urlacher, G; Haussmann, U; Broven, A.; Wemmer, K. (1994). "The Darfur Dome, western Sudan: the product of a subcontinental mantle plume". Geologische Rundschau 83 (3): 614–623. doi:10.1007/BF01083232. Bibcode: 1994GeoRu..83..614F. https://link.springer.com/article/10.1007/BF01083232. 
  2. ↑ 2.0 2.1 2.2 Franz, G.; Steiner, G.; Volker, F.; Pudlo, D.; Hammerschmidt, K. (1999). "Plume related alkaline magmatism in central Africa—the Meidob Hills (W Sudan)". Chemical Geology 157 (1–2): 27–47. doi:10.1016/S0009-2541(98)00195-8. Bibcode: 1999ChGeo.157...27F. https://www.sciencedirect.com/science/article/abs/pii/S0009254198001958. 
  3. ↑ 3.0 3.1 Burke, K. (1996). "The African plate". South African Journal of Geology 99 (4): 339–410. https://journals.co.za/content/journal/10520/EJC-942801f20. 
  4. ↑ 4.0 4.1 Ebinger, C.J.; Sleep, N.H. (1998). "Cenozoic magmatism throughout east Africa resulting from impact of a single plume". Nature 395 (6704): 788–791. doi:10.1038/27417. Bibcode: 1998Natur.395..788E. https://www.nature.com/articles/27417. 
  5. ↑ 5.0 5.1 Zhao, D (2007). "Seismic images under 60 hotspots: Search for mantle plumes". Gondwana Research 12 (4): 335–355. doi:10.1016/j.gr.2007.03.001. Bibcode: 2007GondR..12..335Z. https://www.sciencedirect.com/science/article/pii/S1342937X0700055X. 
  6. ↑ 6.0 6.1 Steinberger, B. (2000). "Plumes in a convecting mantle: Models and observations for individual hotspots". Journal of Geophysical Research 105 (B5): 11127–11152. doi:10.1029/1999JB900398. Bibcode: 2000JGR...10511127S. 
  7. ↑ 7.0 7.1 King, S.D.; Ritsema, J. (2000). "African hot spot volcanism: Small-scale convection in the upper mantle beneath cratons". Science 290 (5494): 1137–1140. doi:10.1126/science.290.5494.1137. PMID 11073447. Bibcode: 2000Sci...290.1137K. https://www.science.org/doi/10.1126/science.290.5494.1137. 
  8. ↑ 8.0 8.1 Sebai, A.; Stutzmann, E.; Montagner, J-P.; Sicilia, D.; Beucler, E. (2006). "Anisotropic structure of the African upper mantle from Rayleigh and Love wave tomography". Physics of the Earth and Planetary Interiors 155 (1–2): 48–62. doi:10.1016/j.pepi.2005.09.009. Bibcode: 2006PEPI..155...48S. https://www.sciencedirect.com/science/article/pii/S0031920105002281. 
  9. ↑ 9.0 9.1 Montagner, J-P.; Marty, B.; Stutzmann, E.; Sicilia, D.; Cara, M.; Pik, R.; Lévêque, J-J.; Roult, G. et al. (2007). "Mantle upwellings and convective instabilities revealed by seismic tomography and helium isotope geochemistry beneath eastern Africa". Geophysical Research Letters 34 (21). doi:10.1029/2007GL031098. Bibcode: 2007GeoRL..3421303M. 
  10. ↑ Sicilia, D.; Montagner, J-P.; Cara, M.; Stutzmann, E.; Debayle, E.; Lépinea, J-C.; Lévêque, J-J.; Beucler, E. et al. (2008). "Upper mantle structure of shear-waves velocities and stratification of anisotropy in the Afar Hotspot region". Tectonophysics 462 (1–4): 164–177. doi:10.1016/j.tecto.2008.02.016. Bibcode: 2008Tectp.462..164S. https://www.sciencedirect.com/science/article/pii/S0040195108003673. 

[ ⚑ ] 13°5′0″N 24°20′0″E / 13.083333°N 24.333333°E / 13.083333; 24.333333




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