Darfur Dome

{{Use dmy dates|date=March 2020}}

File:EFS highres STS026 STS026-42-23.JPG.]]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.{{cite journal |last1=Franz |first1=G. |last2=Pudlo |first2=D. |last3=Urlacher |first3=G |last4=Haussmann |first4=U |last5=Broven | first5=A. |last6=Wemmer |first6=K. |date=1994 |title=The Darfur Dome, western Sudan: the product of a subcontinental mantle plume |url=https://link.springer.com/article/10.1007/BF01083232 |journal=Geologische Rundschau |volume=83 |issue=3 |pages=614–623 |doi=10.1007/BF01083232|bibcode=1994GeoRu..83..614F |s2cid=198144219 |url-access=subscription }}

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.{{cite journal |last1=Franz |first1=G. |last2=Steiner |first2=G. |last3=Volker |first3=F. |last4=Pudlo |first4=D. |last5=Hammerschmidt | first5=K. |date=1999 |title=Plume related alkaline magmatism in central Africa—the Meidob Hills (W Sudan) |url=https://www.sciencedirect.com/science/article/abs/pii/S0009254198001958 |journal=Chemical Geology |volume=157 |issue=1–2 |pages=27–47 |doi=10.1016/S0009-2541(98)00195-8|bibcode=1999ChGeo.157...27F |url-access=subscription }} Evidence for a plume origin includes domal uplift, gravity anomalies, and low seismic velocity zones in the mantle,{{cite journal |last1=Burke |first1=K. |date=1996 |title=The African plate |url=https://journals.co.za/content/journal/10520/EJC-942801f20 |journal=South African Journal of Geology |volume=99 |issue=4 |pages=339–410}}{{cite journal |last1=Ebinger |first1=C.J. |last2=Sleep |first2=N.H. |date=1998 |title=Cenozoic magmatism throughout east Africa resulting from impact of a single plume |url=https://www.nature.com/articles/27417 |journal=Nature |volume=395 |issue=6704 |pages=788–791 |doi=10.1038/27417|bibcode=1998Natur.395..788E |s2cid=4379613 |url-access=subscription }}{{cite journal |last1=Zhao |first1=D |date=2007 |title=Seismic images under 60 hotspots: Search for mantle plumes |url=https://www.sciencedirect.com/science/article/pii/S1342937X0700055X |journal=Gondwana Research |volume=12 |issue=4 |pages=335–355 |doi=10.1016/j.gr.2007.03.001|bibcode=2007GondR..12..335Z |url-access=subscription }}{{cite journal |last1=Steinberger |first1=B. |date=2000 |title=Plumes in a convecting mantle: Models and observations for individual hotspots |journal=Journal of Geophysical Research |volume=105 |issue=B5 |pages=11127–11152 |doi=10.1029/1999JB900398|bibcode=2000JGR...10511127S |doi-access=free }} though there is disagreement over whether these indicate a discreet, narrow plume under the Darfur region or a broad superplume with conduits feeding several African hotspots.

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.{{cite journal |last1=King |first1=S.D. |last2=Ritsema |first2=J. |date=2000 |title=African hot spot volcanism: Small-scale convection in the upper mantle beneath cratons |url=https://www.science.org/doi/10.1126/science.290.5494.1137 |journal=Science |volume=290 |issue=5494 |pages=1137–1140 |doi=10.1126/science.290.5494.1137|pmid=11073447 |bibcode=2000Sci...290.1137K |url-access=subscription }}{{cite journal |last1=Sebai |first1=A. |last2=Stutzmann |first2=E. |last3=Montagner |first3=J-P. |last4=Sicilia |first4=D. |last5=Beucler |first5=E. |date=2006 |title=Anisotropic structure of the African upper mantle from Rayleigh and Love wave tomography |url=https://www.sciencedirect.com/science/article/pii/S0031920105002281 |journal=Physics of the Earth and Planetary Interiors |volume=155 |issue=1–2 |pages=48–62 |doi=10.1016/j.pepi.2005.09.009|bibcode=2006PEPI..155...48S |url-access=subscription }}{{cite journal |last1=Montagner |first1=J-P. |last2=Marty |first2=B. |last3=Stutzmann |first3=E. |last4=Sicilia |first4=D. |last5=Cara | first5=M. |last6=Pik |first6=R. |last7=Lévêque |first7=J-J. |last8=Roult |first8=G. |last9=Beucler |first9=E. |last10=Debayle |first10=E. |date=2007 |title=Mantle upwellings and convective instabilities revealed by seismic tomography and helium isotope geochemistry beneath eastern Africa |journal=Geophysical Research Letters |volume=34 |issue=21 |doi=10.1029/2007GL031098|bibcode=2007GeoRL..3421303M |doi-access=free }}{{cite journal |last1=Sicilia |first1=D. |last2=Montagner |first2=J-P. |last3=Cara |first3=M. |last4=Stutzmann |first4=E. |last5=Debayle | first5=E. |last6=Lépinea |first6=J-C. |last7=Lévêque |first7=J-J. |last8=Beucler |first8=E. |last9=Sebai |first9=A. |last10=Roult |first10=G. |last11=Ayele |first11=A. |last12=Sholan |first12=J.M. |date=2008 |title=Upper mantle structure of shear-waves velocities and stratification of anisotropy in the Afar Hotspot region |url=https://www.sciencedirect.com/science/article/pii/S0040195108003673 |journal=Tectonophysics |volume=462 |issue=1–4 |pages=164–177 |doi=10.1016/j.tecto.2008.02.016|bibcode=2008Tectp.462..164S |url-access=subscription }} This interpretation is supported by high seismic shear wave velocities which indicate shallow, cold downwellings as well as normal heat-flow and low helium isotope ratios.

File:Deriba Caldera.jpg|Deriba Caldera

file:Sudan Jebel Marra Deriba Lakes edited.jpg|Jebel Marra Deriba Lakes

File:Central African Shear Zone.svg|Central Africa showing CASZ.