The initiation of segmented buoyancy-driven melting during continental breakup

被引：0

作者：

Ryan J. Gallacher

Derek Keir

Nicholas Harmon

Graham Stuart

Sylvie Leroy

James O. S. Hammond

J-Michael Kendall

Atalay Ayele

Berhe Goitom

Ghebrebrhan Ogubazghi

Abdulhakim Ahmed

机构：

[1] Ocean and Earth Science,Dipartimento di Scienze della Terra

[2] National Oceanography Centre Southampton,Department of Earth and Planetary Sciences

[3] University of Southampton,undefined

[4] Università degli Studi di Firenze,undefined

[5] School of Earth and Environment,undefined

[6] University of Leeds,undefined

[7] Sorbonne Universités,undefined

[8] UPMC - ISTEP - CNRS UMR7193,undefined

[9] Birkbeck,undefined

[10] University of London,undefined

[11] School of Earth Sciences,undefined

[12] University of Bristol,undefined

[13] Institute of Geophysics,undefined

[14] Space and Astronomy,undefined

[15] Addis Ababa University,undefined

[16] Eritrea Institute of Technology,undefined

[17] Seismological and Volcanological Observatory Center,undefined

来源：

Nature Communications | / 7卷

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摘要：

Melting of the mantle during continental breakup leads to magmatic intrusion and volcanism, yet our understanding of the location and dominant mechanisms of melt generation in rifting environments is impeded by a paucity of direct observations of mantle melting. It is unclear when during the rifting process the segmented nature of magma supply typical of seafloor spreading initiates. Here, we use Rayleigh-wave tomography to construct a high-resolution absolute three-dimensional shear-wave velocity model of the upper 250 km beneath the Afar triple junction, imaging the mantle response during progressive continental breakup. Our model suggests melt production is highest and melting depths deepest early during continental breakup. Elevated melt production during continental rifting is likely due to localized thinning and melt focusing when the rift is narrow. In addition, we interpret segmented zones of melt supply beneath the rift, suggesting that buoyancy-driven active upwelling of the mantle initiates early during continental rifting.

引用

共 132 条

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