Cenozoic magmatism throughout east Africa resulting from impact of a single plume

Ebinger, C. J.; Sleep, Norman H.

doi:10.1038/27417

Cited by 765 publications

(604 citation statements)

References 33 publications

Supporting

Mentioning

570

Contrasting

Unclassified

Order By: Relevance

“…The most prominent of these models is the suggested diversion of hot mantle material from the Afar plume in East Africa through the CASZ to the CVL (Figure 13b) [Ebinger and Sleep, 1998]. This process, however, should create an age progression from older volcanics in the east to younger volcanics in the west, which is not observed.…”

Section: 1002/2014jb011580mentioning

confidence: 99%

“…Some models evoke single or multiple mantle plumes [Ngako et al, 2006], others suggest that pre-existing lithospheric structures control the formation of the CVL [Ebinger and Sleep, 1998], and a large class of proposed models rely on convection driven by various forces to form the CVL (Figure 13) Anderson, 1995, 1998;Meyers et al, 1998;King and Ritsema, 2000]. Here we briefly describe these models and the implications that results from previous studies and this study have for their viability.…”

Section: Models For the Formation Of The Cameroon Volcanic Linementioning

confidence: 99%

“…Numerous studies have noted that the CVL does not display a clear age progression along the line as is exhibited by "typical" hot spot chains [e.g., Hedberg, 1969;Grant et al, 1972;Grunau et al, 1975;Dunlop and Fitton, 1979;Cornen and Maury, 1980;Dunlop, 1983;Fitton and Dunlop, 1985;Lee et al, 1994;Ngounouno et al, 1997;Marzoli et al, 1999Marzoli et al, , 2000Ngounouno et al, 2001Ngounouno et al, , 2003Njilah et al, 2004;Ngounouno et al, 2005Ngounouno et al, , 2006Aka et al, 2009;Dongmo et al, 2010;Kamgang et al, 2010;see Njome and de Wit, 2014, Figure 2]. The absence of age progression along the line has led to much debate over the geodynamic origin of this feature, with suggested formation mechanisms ranging from multiple mantle plumes [Ngako et al, 2006], to reactivation of previously existing shear zones [Ebinger and Sleep, 1998], to mantle upwellings driven by convection currents of various sources Anderson, 1995, 1998;Meyers et al, 1998;King and Ritsema, 2000].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Lithospheric instability and the source of the Cameroon Volcanic Line: Evidence from Rayleigh wave phase velocity tomography

et al. 2015

View full text Add to dashboard Cite

The Cameroon Volcanic Line (CVL) is a 1800 km long volcanic chain, extending SW-NE from the Gulf of Guinea into Central Africa, that lacks the typical age progression exhibited by hot spot-related volcanic tracks. This study investigates the upper mantle seismic structure beneath the CVL and surrounding regions to constrain the origin of volcanic lines that are poorly described by the classic plume model. Rayleigh wave phase velocities are measured at periods from 20 to 182 s following the two-plane wave methodology, using data from the Cameroon Seismic Experiment, which consists of 32 broadband stations deployed between 2005 and 2007. These phase velocities are then inverted to build a model of shear wave velocity structure in the upper mantle beneath the CVL. Results show that phase velocities beneath the CVL are reduced at all periods, with average velocities beneath the CVL deviating more than -2% from the regional average and +4% beneath the Congo Craton. This distinction is observed for all periods but is less pronounced for the longest periods measured. Inversion for shear wave velocity structure indicates a tabular low velocity anomaly directly beneath the CVL at depths of 50 to at least 200 km and a sharp vertical boundary with faster velocities beneath the Congo Craton. These observations demonstrate widespread infiltration or erosion of the continental lithosphere beneath the CVL, most likely caused by mantle upwelling associated with edge-flow convection driven by the Congo Craton or by lithospheric instabilities that develop due to the nearby edge of the African continent.

show abstract

Section: 1002/2014jb011580mentioning

confidence: 99%

Section: Models For the Formation Of The Cameroon Volcanic Linementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Lithospheric instability and the source of the Cameroon Volcanic Line: Evidence from Rayleigh wave phase velocity tomography

et al. 2015

View full text Add to dashboard Cite

show abstract

“…1 inset;Hoffman et al 1997;Ebinger & Sleep 1998;Courtillot et al 1999). From ∼25 to 20 Ma, while oceanic spreading developed in the RS and the AR, continental extension started in the Afar Depression (AD, Wolfenden et al 2005).…”

Section: The Triple-rift Junction In Afarmentioning

confidence: 99%

Current deformation in Central Afar and triple junction kinematics deduced from GPS and InSAR measurements

Doubre¹,

Déprez²,

Masson³

et al. 2016

Geophys. J. Int.

View full text Add to dashboard Cite

S U M M A R YKinematics of divergent boundaries and Rift-Rift-Rift junctions are classically studied using long-term geodetic observations. Since significant magma-related displacements are expected, short-term deformation provides important constraints on the crustal mechanisms involved both in active rifting and in transfer of extensional deformation between spreading axes. Using InSAR and GPS data, we analyse the surface deformation in the whole Central Afar region in detail, focusing on both the extensional deformation across the Quaternary magmato-tectonic rift segments, and on the zones of deformation transfer between active segments and spreading axes. The largest deformation occurs across the two recently activated Asal-Ghoubbet (AG) and Manda Hararo-Dabbahu (MH-D) magmato-tectonic segments with very high strain rates, whereas the other Quaternary active segments do not concentrate any large strain, suggesting that these rifts are either sealed during interdyking periods or not mature enough to remain a plate boundary. Outside of these segments, the GPS horizontal velocity field shows a regular gradient following a clockwise rotation of the displacements from the Southeast to the East of Afar, with respect to Nubia. Very few shallow creeping structures can be identified as well in the InSAR data. However, using these data together with the strain rate tensor and the rotations rates deduced from GPS baselines, the present-day strain field over Central Afar is consistent with the main tectonic structures, and therefore with the long-term deformation. We investigate the current kinematics of the triple junction included in our GPS data set by building simple block models. The deformation in Central Afar can be described by adding a central microblock evolving separately from the three surrounding plates. In this model, the northern block boundary corresponds to a deep EW-trending trans-tensional dislocation, locked from the surface to 10-13 km and joining at depth the active spreading axes of the Red Sea and the Aden Ridge, from AG to MH-D rift segments. Over the long-term, this plate configuration could explain the presence of the en-échelon magmatic basins and subrifts. However, the transient behaviour of the spreading axes implies that the deformation in Central Afar evolves depending on the availability of magma supply within the well-established segments.

show abstract

“…Localized melting may be expected to occur beneath the Rungwe region due to a variety of mechanisms including thermal or compositional anomalies in the upper mantle, thinning of the lithosphere from Neogene-recent rifting, pre-thinning of the lithosphere prior to present rifting, or a combination of the above. Ebinger & Sleep (1998) model the flow of upwelling mantle plume beneath variable thickness lithosphere, and predict enhanced melting beneath the margins of the deeply rooted Tanzania and Congo cratons. Regions of pre-existing weakness and/or thin lithosphere are proposed to control lateral transport of hot plume material and where it ponds and escapes to the surface as a volcanic centre, as seen along the Western Branch (e.g.…”

Section: The Rungwe Volcanic Province: the Localization Of Magmatism mentioning

confidence: 99%

Surface wave imaging of the weakly extended Malawi Rift from ambient-noise and teleseismic Rayleigh waves from onshore and lake-bottom seismometers

Accardo

Gaherty

Shillington

et al. 2017

Geophysical Journal International

View full text Add to dashboard Cite

Cenozoic magmatism throughout east Africa resulting from impact of a single plume

Cited by 765 publications

References 33 publications

Lithospheric instability and the source of the Cameroon Volcanic Line: Evidence from Rayleigh wave phase velocity tomography

Lithospheric instability and the source of the Cameroon Volcanic Line: Evidence from Rayleigh wave phase velocity tomography

Current deformation in Central Afar and triple junction kinematics deduced from GPS and InSAR measurements

Surface wave imaging of the weakly extended Malawi Rift from ambient-noise and teleseismic Rayleigh waves from onshore and lake-bottom seismometers

Contact Info

Product

Resources

About