Upper mantle structure of the Saharan Metacraton

Abdelsalam, Mohamed G.; Gao, Stephen S.; Liégeois, Jean-Paul

doi:10.1016/j.jafrearsci.2011.03.009

Cited by 91 publications

(62 citation statements)

References 68 publications

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“…Although heterogeneous at the surface (Fig. 14), its homogeneity at the lithospheric scale has been recently demonstrated by geophysical data, the Saharan metacraton presenting a peculiar lithospheric structure, nearly unique in the world (Abdelsalam et al, 2011). Looking at its continental size (Fig.…”

Section: The Complex Case Of the Saharan Metacraton (Africa)mentioning

confidence: 89%

Metacraton: Nature, genesis and behavior

et al. 2013

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Section: The Complex Case Of the Saharan Metacraton (Africa)mentioning

confidence: 89%

Metacraton: Nature, genesis and behavior

et al. 2013

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“…25°N it separates outcrops of the ANS from much older terranes of the Saharan Metacraton ( Fig. 2; Abdelsalam et al, 2002Abdelsalam et al, , 2003. Between lat.…”

Section: The Arabo-nubian Shield (Ans)mentioning

confidence: 97%

“…Basement exposures west of the Keraf suture contain much N1.8 Ga crustal material, usually reworded by the Pan African orogeny, assigned to the "East Saharan ghost craton" (Black and Liégeois, 1993) or "Saharan Metacraton" (Abdelsalam et al, 2002)-names emphasizing the abundance of reworked old crust. The Metacraton is quite heterogeneous and is most likely built of a collage of distinct terranes rather than a single reworked unit, but discontinuous basement exposure and incomplete knowledge permit only a partial picture to be discerned.…”

Section: The Saharan Metacratonmentioning

confidence: 99%

The relations between Gondwana and the adjacent peripheral Cadomian domain—constrains on the origin, history, and paleogeography of the peripheral domain

Garfunkel

2015

Gondwana Research

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“…Reconstructions of past plate motion come from surface geological mapping, geochemical, geochronological, and geophysical studies [Abdelsalam et al, 2011;Begg et al, 2009;De Waele et al, 2009;Johnson et al, 2006;Pasyanos and Nyblade, 2007;Ritsema et al, 1998;Ritsema and van Heijst, 2000]. However, substantial uncertainties in reconstructing continents over geologic timescales exist as continental tectonic elements experienced heavy structural alteration, high degrees of metamorphism, erosion and sedimentary cover [Abdelsalam et al, 2002;Artemieva and Mooney, 2001;Daly, 1986;De Waele et al, 2008;Johnson et al, 2005;Liégeois et al, 2013].…”

Section: Oceanic Plate Motionmentioning

confidence: 99%

“…In Africa, which in many reconstructions is put as the heart of Greater Gondwana [Irving and Irving, 1982;Smith and Hallam, 1970], surface geological mapping, geochemical and geochronological studies together with low resolution seismic tomography [Abdelsalam et al, 2011;Begg et al, 2009;Deen et al, 2006;Lebedev et al, 2009;Pasyanos, 2010;Pasyanos and Nyblade, 2007;Ritsema and van Heijst, 2000;Shapiro and Ritzwoller, 2002] have resulted in establishing the extent of major cratons and orogenic belts of Greater Gondwana (Fig. 1A).…”

Section: Introductionmentioning

confidence: 99%

Geophysical and petrological constraints on ocean plate dynamics

Sarafian¹

2017

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This thesis investigates the formation and subsequent motion of oceanic lithospheric plates through geophysical and petrological methods. Ocean crust and lithosphere forms at mid-ocean ridges as the underlying asthenosphere rises, melts, and flows away from the ridge axis. In Chapters 2 and 3, I present the results from partial melting experiments of mantle peridotite that were conducted in order to examine the mantle melting point, or solidus, beneath a mid-ocean ridge. Chapter 2 determines the peridotite solidus at a single pressure of 1.5 GPa and concludes that the oceanic mantle potential temperature must be ~60 ºC hotter than current estimates. Chapter 3 goes further to provide a more accurate parameterization of the anhydrous mantle solidus from experiments over a range of pressures. This chapter concludes that the range of potential temperatures of the mantle beneath mid-ocean ridges and plumes is smaller than currently estimated. Once formed, the oceanic plate moves atop the underlying asthenosphere away from the ridge axis. Chapter 4 uses seafloor magnetotelluric data to investigate the mechanism responsible for plate motion at the lithosphere-asthenosphere boundary. The resulting two dimensional conductivity model shows a simple layered structure. By applying petrological constraints, I conclude that the upper asthenosphere does not contain substantial melt, which suggests that either a thermal or hydration mechanism supports plate motion. Oceanic plate motion has dramatically changed the surface of the Earth over time, and evidence for ancient plate motion is obvious from detailed studies of the longer lived continental lithosphere. In Chapter 5, I investigate past plate motion by inverting magnetotelluric data collected over eastern Zambia. The conductivity model probes the Zambian lithosphere and reveals an ancient subduction zone previously suspected from surface studies. This chapter elucidates the complex lithospheric structure of eastern Zambia and the geometry of the tectonic elements in the region, which collided as a result of past oceanic plate motion. Combined, the chapters of this thesis provide critical constraints on ocean plate dynamics.

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Upper mantle structure of the Saharan Metacraton

Cited by 91 publications

References 68 publications

Metacraton: Nature, genesis and behavior

Metacraton: Nature, genesis and behavior

The relations between Gondwana and the adjacent peripheral Cadomian domain—constrains on the origin, history, and paleogeography of the peripheral domain

Geophysical and petrological constraints on ocean plate dynamics

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