Upper mantle temperature and the onset of extension and break-up in Afar, Africa. / Armitage, John; Ferguson, David; Goes, Saskia; Hammond, James; Calais, Eric; Rychert, Catherine; Harmon, Nicholas.

In: Earth and Planetary Science Letters, Vol. 418, 15.05.2015, p. 78-90.

Research output: Contribution to journalArticlepeer-review

Published

Standard

Upper mantle temperature and the onset of extension and break-up in Afar, Africa. / Armitage, John; Ferguson, David; Goes, Saskia; Hammond, James; Calais, Eric; Rychert, Catherine; Harmon, Nicholas.

In: Earth and Planetary Science Letters, Vol. 418, 15.05.2015, p. 78-90.

Research output: Contribution to journalArticlepeer-review

Harvard

Armitage, J, Ferguson, D, Goes, S, Hammond, J, Calais, E, Rychert, C & Harmon, N 2015, 'Upper mantle temperature and the onset of extension and break-up in Afar, Africa', Earth and Planetary Science Letters, vol. 418, pp. 78-90. https://doi.org/10.1016/j.epsl.2015.02.039

APA

Armitage, J., Ferguson, D., Goes, S., Hammond, J., Calais, E., Rychert, C., & Harmon, N. (2015). Upper mantle temperature and the onset of extension and break-up in Afar, Africa. Earth and Planetary Science Letters, 418, 78-90. https://doi.org/10.1016/j.epsl.2015.02.039

Vancouver

Armitage J, Ferguson D, Goes S, Hammond J, Calais E, Rychert C et al. Upper mantle temperature and the onset of extension and break-up in Afar, Africa. Earth and Planetary Science Letters. 2015 May 15;418:78-90. https://doi.org/10.1016/j.epsl.2015.02.039

Author

Armitage, John ; Ferguson, David ; Goes, Saskia ; Hammond, James ; Calais, Eric ; Rychert, Catherine ; Harmon, Nicholas. / Upper mantle temperature and the onset of extension and break-up in Afar, Africa. In: Earth and Planetary Science Letters. 2015 ; Vol. 418. pp. 78-90.

BibTeX

@article{79237e01cc464da0af49f1e6196f2b9e,
title = "Upper mantle temperature and the onset of extension and break-up in Afar, Africa",
abstract = "It is debated to what extent mantle plumes play a role in continental rifting and eventual break-up. Afar lies at the northern end of the largest and most active present-day continental rift, where the East African Rift forms a triple junction with the Red Sea and Gulf of Aden rifts. It has a history of plume activity yet recent studies have reached conflicting conclusions on whether a plume still contributes to current Afar tectonics. A geochemical study concluded that Afar is a mature hot rift with 80 km thick lithosphere, while seismic data have been interpreted to reflect the structure of a young, oceanic rift basin above mantle of normal temperature. We develop a self-consistent forward model of mantle flow that incorporates melt generation and retention to test whether predictions of melt chemistry, melt volume and lithosphere–asthenosphere seismic structure can be reconciled with observations. The rare-earth element composition of mafic samples at the Erta Ale, Dabbahu and Asal magmatic segments can be used as both a thermometer and chronometer of the rifting process. Low seismic velocities require a lithosphere thinned to 50 km or less. A strong positive impedance contrast at 50 to 70 km below the rift seems linked to the melt zone, but is not reproduced by isotropic seismic velocity alone. Combined, the simplest interpretation is that mantle temperature below Afar is still elevated at 1450 ◦C, rifting started around 22–23 Ma, and the lithosphere has thinned from 100 to 50 km to allow significant decompressional melting.",
author = "John Armitage and David Ferguson and Saskia Goes and James Hammond and Eric Calais and Catherine Rychert and Nicholas Harmon",
year = "2015",
month = may,
day = "15",
doi = "10.1016/j.epsl.2015.02.039",
language = "English",
volume = "418",
pages = "78--90",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Upper mantle temperature and the onset of extension and break-up in Afar, Africa

AU - Armitage, John

AU - Ferguson, David

AU - Goes, Saskia

AU - Hammond, James

AU - Calais, Eric

AU - Rychert, Catherine

AU - Harmon, Nicholas

PY - 2015/5/15

Y1 - 2015/5/15

N2 - It is debated to what extent mantle plumes play a role in continental rifting and eventual break-up. Afar lies at the northern end of the largest and most active present-day continental rift, where the East African Rift forms a triple junction with the Red Sea and Gulf of Aden rifts. It has a history of plume activity yet recent studies have reached conflicting conclusions on whether a plume still contributes to current Afar tectonics. A geochemical study concluded that Afar is a mature hot rift with 80 km thick lithosphere, while seismic data have been interpreted to reflect the structure of a young, oceanic rift basin above mantle of normal temperature. We develop a self-consistent forward model of mantle flow that incorporates melt generation and retention to test whether predictions of melt chemistry, melt volume and lithosphere–asthenosphere seismic structure can be reconciled with observations. The rare-earth element composition of mafic samples at the Erta Ale, Dabbahu and Asal magmatic segments can be used as both a thermometer and chronometer of the rifting process. Low seismic velocities require a lithosphere thinned to 50 km or less. A strong positive impedance contrast at 50 to 70 km below the rift seems linked to the melt zone, but is not reproduced by isotropic seismic velocity alone. Combined, the simplest interpretation is that mantle temperature below Afar is still elevated at 1450 ◦C, rifting started around 22–23 Ma, and the lithosphere has thinned from 100 to 50 km to allow significant decompressional melting.

AB - It is debated to what extent mantle plumes play a role in continental rifting and eventual break-up. Afar lies at the northern end of the largest and most active present-day continental rift, where the East African Rift forms a triple junction with the Red Sea and Gulf of Aden rifts. It has a history of plume activity yet recent studies have reached conflicting conclusions on whether a plume still contributes to current Afar tectonics. A geochemical study concluded that Afar is a mature hot rift with 80 km thick lithosphere, while seismic data have been interpreted to reflect the structure of a young, oceanic rift basin above mantle of normal temperature. We develop a self-consistent forward model of mantle flow that incorporates melt generation and retention to test whether predictions of melt chemistry, melt volume and lithosphere–asthenosphere seismic structure can be reconciled with observations. The rare-earth element composition of mafic samples at the Erta Ale, Dabbahu and Asal magmatic segments can be used as both a thermometer and chronometer of the rifting process. Low seismic velocities require a lithosphere thinned to 50 km or less. A strong positive impedance contrast at 50 to 70 km below the rift seems linked to the melt zone, but is not reproduced by isotropic seismic velocity alone. Combined, the simplest interpretation is that mantle temperature below Afar is still elevated at 1450 ◦C, rifting started around 22–23 Ma, and the lithosphere has thinned from 100 to 50 km to allow significant decompressional melting.

U2 - 10.1016/j.epsl.2015.02.039

DO - 10.1016/j.epsl.2015.02.039

M3 - Article

VL - 418

SP - 78

EP - 90

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

ER -