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Darfur Dome

Coordinates: 13°5′0″N 24°20′0″E / 13.08333°N 24.33333°E / 13.08333; 24.33333
From Wikipedia, the free encyclopedia

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]

Notes

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  1. ^ a b c d 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. Bibcode:1994GeoRu..83..614F. doi:10.1007/BF01083232. S2CID 198144219.
  2. ^ a b c 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. Bibcode:1999ChGeo.157...27F. doi:10.1016/S0009-2541(98)00195-8.
  3. ^ a b Burke, K. (1996). "The African plate". South African Journal of Geology. 99 (4): 339–410.
  4. ^ a b Ebinger, C.J.; Sleep, N.H. (1998). "Cenozoic magmatism throughout east Africa resulting from impact of a single plume". Nature. 395 (6704): 788–791. Bibcode:1998Natur.395..788E. doi:10.1038/27417. S2CID 4379613.
  5. ^ a b Zhao, D (2007). "Seismic images under 60 hotspots: Search for mantle plumes". Gondwana Research. 12 (4): 335–355. Bibcode:2007GondR..12..335Z. doi:10.1016/j.gr.2007.03.001.
  6. ^ a b Steinberger, B. (2000). "Plumes in a convecting mantle: Models and observations for individual hotspots". Journal of Geophysical Research. 105 (B5): 11127–11152. Bibcode:2000JGR...10511127S. doi:10.1029/1999JB900398.
  7. ^ a b King, S.D.; Ritsema, J. (2000). "African hot spot volcanism: Small-scale convection in the upper mantle beneath cratons". Science. 290 (5494): 1137–1140. Bibcode:2000Sci...290.1137K. doi:10.1126/science.290.5494.1137. PMID 11073447.
  8. ^ a b 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. Bibcode:2006PEPI..155...48S. doi:10.1016/j.pepi.2005.09.009.
  9. ^ a b Montagner, J-P.; Marty, B.; Stutzmann, E.; Sicilia, D.; Cara, M.; Pik, R.; Lévêque, J-J.; Roult, G.; Beucler, E.; Debayle, E. (2007). "Mantle upwellings and convective instabilities revealed by seismic tomography and helium isotope geochemistry beneath eastern Africa". Geophysical Research Letters. 34 (21). Bibcode:2007GeoRL..3421303M. doi:10.1029/2007GL031098.
  10. ^ Sicilia, D.; Montagner, J-P.; Cara, M.; Stutzmann, E.; Debayle, E.; Lépinea, J-C.; Lévêque, J-J.; Beucler, E.; Sebai, A.; Roult, G.; Ayele, A.; Sholan, J.M. (2008). "Upper mantle structure of shear-waves velocities and stratification of anisotropy in the Afar Hotspot region". Tectonophysics. 462 (1–4): 164–177. Bibcode:2008Tectp.462..164S. doi:10.1016/j.tecto.2008.02.016.

13°5′0″N 24°20′0″E / 13.08333°N 24.33333°E / 13.08333; 24.33333