Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean
In the North Atlantic Ocean, the geometry of diachronous V-shaped features that straddle the Reykjanes Ridge is often attributed to thermal pulses which advect away from the center of the Iceland plume. Recently, two alternative hypotheses have been proposed: rift propagation and buoyant mantle upwe...
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ftsouthampton:oai:eprints.soton.ac.uk:414347 2023-07-30T04:04:26+02:00 Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean Parnell-Turner, Ross White, Nicky Henstock, Timothy J. Jones, Stephen M. Maclennan, John Murton, Bramley J. 2017-11-14 text https://eprints.soton.ac.uk/414347/ https://eprints.soton.ac.uk/414347/1/807322_2_merged_1502304416.pdf https://eprints.soton.ac.uk/414347/2/Parnell_Turner_et_al_2017_Journal_of_Geophysical_Research_Solid_Earth.pdf en English eng https://eprints.soton.ac.uk/414347/1/807322_2_merged_1502304416.pdf https://eprints.soton.ac.uk/414347/2/Parnell_Turner_et_al_2017_Journal_of_Geophysical_Research_Solid_Earth.pdf Parnell-Turner, Ross, White, Nicky, Henstock, Timothy J., Jones, Stephen M., Maclennan, John and Murton, Bramley J. (2017) Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean. Journal of Geophysical Research: Solid Earth, 122 (11), 8675–8708. (doi:10.1002/2017jb014225 <http://dx.doi.org/10.1002/2017jb014225>). Article PeerReviewed 2017 ftsouthampton https://doi.org/10.1002/2017jb014225 2023-07-09T22:17:56Z In the North Atlantic Ocean, the geometry of diachronous V-shaped features that straddle the Reykjanes Ridge is often attributed to thermal pulses which advect away from the center of the Iceland plume. Recently, two alternative hypotheses have been proposed: rift propagation and buoyant mantle upwelling. Here, we evaluate these different proposals using basin-wide geophysical and geochemical observations. The centerpiece of our analysis is a pair of seismic reflection profiles oriented parallel to flowlines that span the North Atlantic Ocean. V-shaped ridges and troughs are mapped on both Neogene and Paleogene oceanic crust, enabling a detailed chronology of activity to be established for the last 50 million years. Estimates of the cumulative horizontal displacement across normal faults help to discriminate between brittle and magmatic modes of plate separation, suggesting that crustal architecture is sensitive to the changing planform of the plume. Water-loaded residual depth measurements are used to estimate crustal thickness and to infer mantle potential temperature which varies by 25◦C on timescales of 3–8 Ma. This variation is consistent with the range of temperatures inferred from geochemical modeling of dredged basaltic rocks along the ridge axis itself, from changes in Neogene deep-water circulation, and from the regional record of episodic Cenozoic magmatism. We conclude that radial propagation of transient thermal anomalies within an asthenospheric channel that is 150 50 km thick best accounts for the available geophysical and geochemical observations. Article in Journal/Newspaper Iceland North Atlantic University of Southampton: e-Prints Soton Reykjanes ENVELOPE(-22.250,-22.250,65.467,65.467) Journal of Geophysical Research: Solid Earth 122 11 8675 8708 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
In the North Atlantic Ocean, the geometry of diachronous V-shaped features that straddle the Reykjanes Ridge is often attributed to thermal pulses which advect away from the center of the Iceland plume. Recently, two alternative hypotheses have been proposed: rift propagation and buoyant mantle upwelling. Here, we evaluate these different proposals using basin-wide geophysical and geochemical observations. The centerpiece of our analysis is a pair of seismic reflection profiles oriented parallel to flowlines that span the North Atlantic Ocean. V-shaped ridges and troughs are mapped on both Neogene and Paleogene oceanic crust, enabling a detailed chronology of activity to be established for the last 50 million years. Estimates of the cumulative horizontal displacement across normal faults help to discriminate between brittle and magmatic modes of plate separation, suggesting that crustal architecture is sensitive to the changing planform of the plume. Water-loaded residual depth measurements are used to estimate crustal thickness and to infer mantle potential temperature which varies by 25◦C on timescales of 3–8 Ma. This variation is consistent with the range of temperatures inferred from geochemical modeling of dredged basaltic rocks along the ridge axis itself, from changes in Neogene deep-water circulation, and from the regional record of episodic Cenozoic magmatism. We conclude that radial propagation of transient thermal anomalies within an asthenospheric channel that is 150 50 km thick best accounts for the available geophysical and geochemical observations. |
format |
Article in Journal/Newspaper |
author |
Parnell-Turner, Ross White, Nicky Henstock, Timothy J. Jones, Stephen M. Maclennan, John Murton, Bramley J. |
spellingShingle |
Parnell-Turner, Ross White, Nicky Henstock, Timothy J. Jones, Stephen M. Maclennan, John Murton, Bramley J. Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
author_facet |
Parnell-Turner, Ross White, Nicky Henstock, Timothy J. Jones, Stephen M. Maclennan, John Murton, Bramley J. |
author_sort |
Parnell-Turner, Ross |
title |
Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
title_short |
Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
title_full |
Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
title_fullStr |
Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
title_full_unstemmed |
Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean |
title_sort |
causes and consequences of diachronous v-shaped ridges in the north atlantic ocean |
publishDate |
2017 |
url |
https://eprints.soton.ac.uk/414347/ https://eprints.soton.ac.uk/414347/1/807322_2_merged_1502304416.pdf https://eprints.soton.ac.uk/414347/2/Parnell_Turner_et_al_2017_Journal_of_Geophysical_Research_Solid_Earth.pdf |
long_lat |
ENVELOPE(-22.250,-22.250,65.467,65.467) |
geographic |
Reykjanes |
geographic_facet |
Reykjanes |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_relation |
https://eprints.soton.ac.uk/414347/1/807322_2_merged_1502304416.pdf https://eprints.soton.ac.uk/414347/2/Parnell_Turner_et_al_2017_Journal_of_Geophysical_Research_Solid_Earth.pdf Parnell-Turner, Ross, White, Nicky, Henstock, Timothy J., Jones, Stephen M., Maclennan, John and Murton, Bramley J. (2017) Causes and consequences of diachronous V-shaped ridges in the North Atlantic Ocean. Journal of Geophysical Research: Solid Earth, 122 (11), 8675–8708. (doi:10.1002/2017jb014225 <http://dx.doi.org/10.1002/2017jb014225>). |
op_doi |
https://doi.org/10.1002/2017jb014225 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
122 |
container_issue |
11 |
container_start_page |
8675 |
op_container_end_page |
8708 |
_version_ |
1772815880001945600 |