The initiation of segmented buoyancy driven melting during continental breakup

Ryan Gallacher, Derek Keir, Nicholas Harmon, Graham Stuart, Sylvie Leroy, James Hammond, J M Kendall, Atalay Ayele, Berhe Goitom Gezahegn, Ghebrebrhan Ogubazghi, Ahmed Abdulhakim

Research output: Contribution to journalArticle (Academic Journal)peer-review

24 Citations (Scopus)
318 Downloads (Pure)

Abstract

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. We use Rayleigh-wave tomography to construct the first high-resolution absolute 3-dimensional shear-wave velocity model of the upper 250 kilometres 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 localised thinning and melt focusing when the rift is narrow. Additionally, we interpret segmented zones of melt supply beneath the rift, suggesting that buoyancy driven active upwelling of the mantle initiates early during continental rifting.
Original languageEnglish
Article number13110
Number of pages9
JournalNature Communications
Volume7
DOIs
Publication statusPublished - 18 Oct 2016

Keywords

  • Seismology
  • Tectonics

Fingerprint Dive into the research topics of 'The initiation of segmented buoyancy driven melting during continental breakup'. Together they form a unique fingerprint.

Cite this