Magma-induced axial subsidence during final-stage rifting: Implications for the development of seaward-dipping reflectors
Magma-induced axial subsidence during final-stage rifting: Implications for the development of seaward-dipping reflectors
A consensus is emerging from studies of continental rifts and rifted margins worldwide that significant extension can be accommodated by magma intrusion prior to the development of a new ocean basin. However, the influence of loading from magma intrusion, lava extrusion, and sedimentation on plate flexure and resultant subsidence of the basin is not well understood. We address this issue by using three-dimensional flexural models constrained by geological and geophysical data from the Main Ethiopian Rift and the Afar Depression in East Africa. Model results show that axial mafic intrusions in the crust are able to cause significant downward flexure of the opening rift and that the amount of subsidence increases with decreasing plate strength accompanying progressive plate thinning and heating during continental breakup. This process contributes to the tilting of basaltic flows toward the magma injection axis, forming the typical wedge-shaped seaward-dipping reflector sequences on either side of the eventual rupture site as the new ocean basin forms.
563-571
Corti, G.
400f2e07-cac3-4421-8684-fd12458daa2b
Agostini, A.
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Keir, D.
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van Wijk, J.
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Bastow, I.D.
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Ranalli, G.
d0b42cc1-cf87-48ee-a37b-a504ef0fa9c0
1 May 2015
Corti, G.
400f2e07-cac3-4421-8684-fd12458daa2b
Agostini, A.
f9a2ecaf-b7a5-458f-8260-8e78e7ed506e
Keir, D.
5616f81f-bf1b-4678-a167-3160b5647c65
van Wijk, J.
5af83237-380d-4c36-961c-6dc37aa3486d
Bastow, I.D.
fa3f4d3f-8ec5-4dee-8de5-57d987d8d7ed
Ranalli, G.
d0b42cc1-cf87-48ee-a37b-a504ef0fa9c0
Corti, G., Agostini, A., Keir, D., van Wijk, J., Bastow, I.D. and Ranalli, G.
(2015)
Magma-induced axial subsidence during final-stage rifting: Implications for the development of seaward-dipping reflectors.
Geosphere, 11 (3), .
(doi:10.1130/GES01076.1).
Abstract
A consensus is emerging from studies of continental rifts and rifted margins worldwide that significant extension can be accommodated by magma intrusion prior to the development of a new ocean basin. However, the influence of loading from magma intrusion, lava extrusion, and sedimentation on plate flexure and resultant subsidence of the basin is not well understood. We address this issue by using three-dimensional flexural models constrained by geological and geophysical data from the Main Ethiopian Rift and the Afar Depression in East Africa. Model results show that axial mafic intrusions in the crust are able to cause significant downward flexure of the opening rift and that the amount of subsidence increases with decreasing plate strength accompanying progressive plate thinning and heating during continental breakup. This process contributes to the tilting of basaltic flows toward the magma injection axis, forming the typical wedge-shaped seaward-dipping reflector sequences on either side of the eventual rupture site as the new ocean basin forms.
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Geosphere-2015-Corti-GES01076.1.pdf
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Published date: 1 May 2015
Organisations:
Geology & Geophysics
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Local EPrints ID: 376975
URI: http://eprints.soton.ac.uk/id/eprint/376975
ISSN: 1553-040X
PURE UUID: 0e007c10-9898-4ae1-bae0-ff23c77e3f32
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Date deposited: 12 May 2015 08:17
Last modified: 15 Mar 2024 03:38
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Author:
G. Corti
Author:
A. Agostini
Author:
J. van Wijk
Author:
I.D. Bastow
Author:
G. Ranalli
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