Use of a high-precision gravity survey to understand the formation of oceanic crust and the role of melt at the southern Red Sea rift in Afar, Ethiopia

E. Lewi*, D. Keir, Y. Birhanu, J. Blundy, G. Stuart, T. Wright, E. Calais

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter in a book

12 Citations (Scopus)

Abstract

The Red Sea arm of the triple junction in northeastern Ethiopia provides an opportunity to investigate rift-forming processes at divergent boundaries. In an attempt to study the subsurface, especially the distribution and role of melt in the rifting process, we carried out a high-precision gravity survey with a mean-square error of 0.011 mgal, assisted by differential global positioning system measurements. The profile is 162 km long and strikes ENE-WSW across the southern part of the Red Sea rift at a latitude of approximately 11.75° N. Modelling of the Bouguer anomaly, constrained by a priori information, showed detailed in-rift variations in the crustal structure and the distribution of melt beneath the rift axis. Our interpretation suggested that the process of continental break-up is governed by crustal stretching and rifting accompanied by the emplacement of melt into the lower crust above a lower density upper mantle. In addition, we interpreted the thickness of the crust beneath this part of the rift axis to be 25 km. The subsurface distribution of density beneath the profile shows that the south-central part of the Red Sea rift has modified thinned crust, intruded by high-density material, which resembles the crust formed during seafloor spreading.

Original languageEnglish
Title of host publicationGeological Society Special Publication
PublisherGeological Society of London
Pages165-180
Number of pages16
Volume420
Edition1
DOIs
Publication statusPublished - 2016

Publication series

NameGeological Society Special Publication
Number1
Volume420
ISSN (Print)03058719

Fingerprint Dive into the research topics of 'Use of a high-precision gravity survey to understand the formation of oceanic crust and the role of melt at the southern Red Sea rift in Afar, Ethiopia'. Together they form a unique fingerprint.

Cite this