Lower-crustal intrusion on the north atlantic continental margin
When continents break apart, the rifting is sometimes accompanied by the production of large volumes of molten rock. The total melt volume, however, is uncertain, because only part of it has erupted at the surface. Furthermore, the cause of the magmatism is still disputed—specifically, whether or no...
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:795 2023-05-15T16:10:55+02:00 Lower-crustal intrusion on the north atlantic continental margin White, R. S. Smith, L. K. Roberts, A. W. Christie, P. A. F. Kusznir, N. Team, iSimm 2008 application/pdf http://eprints.esc.cam.ac.uk/795/ http://eprints.esc.cam.ac.uk/795/1/White_Smith_Roberts_Christie_Kusznir_Nature452_%282008%29.pdf https://doi.org/10.1038/nature06687 doi:10.1038 en eng http://eprints.esc.cam.ac.uk/795/1/White_Smith_Roberts_Christie_Kusznir_Nature452_%282008%29.pdf White, R. S. and Smith, L. K. and Roberts, A. W. and Christie, P. A. F. and Kusznir, N. and Team, iSimm (2008) Lower-crustal intrusion on the north atlantic continental margin. Nature, 452. pp. 460-464. DOI doi:10.1038 02 - Geodynamics Geophysics and Tectonics Article PeerReviewed 2008 ftucambridgeesc https://doi.org/10.1038/nature06687 2020-08-27T18:08:40Z When continents break apart, the rifting is sometimes accompanied by the production of large volumes of molten rock. The total melt volume, however, is uncertain, because only part of it has erupted at the surface. Furthermore, the cause of the magmatism is still disputed—specifically, whether or not it is due to increased mantle temperatures. We recorded deep-penetration normal-incidence and wide-angle seismic profiles across the Faroe and Hatton Bank volcanic margins in the northeast Atlantic. Here we show that near the Faroe Islands, for every 1 km along strike, 360–400 km3 of basalt is extruded, while 540–600 km3 is intruded into the continent–ocean transition. We find that lower-crustal intrusions are focused mainly into a narrow zone approx50 km wide on the transition, although extruded basalts flow more than 100 km from the rift. Seismic profiles show that the melt is intruded into the lower crust as sills, which cross-cut the continental fabric, rather than as an 'underplate' of 100 per cent melt, as has often been assumed. Evidence from the measured seismic velocities and from igneous thicknesses are consistent with the dominant control on melt production being increased mantle temperatures, with no requirement for either significant active small-scale mantle convection under the rift or the presence of fertile mantle at the time of continental break-up, as has previously been suggested for the North Atlantic Ocean. Article in Journal/Newspaper Faroe Islands North Atlantic Northeast Atlantic University of Cambridge, Department of Earth Sciences: ESC Publications Faroe Islands Hatton Bank ENVELOPE(-18.000,-18.000,58.583,58.583) Nature 452 7186 460 464 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
02 - Geodynamics Geophysics and Tectonics |
spellingShingle |
02 - Geodynamics Geophysics and Tectonics White, R. S. Smith, L. K. Roberts, A. W. Christie, P. A. F. Kusznir, N. Team, iSimm Lower-crustal intrusion on the north atlantic continental margin |
topic_facet |
02 - Geodynamics Geophysics and Tectonics |
description |
When continents break apart, the rifting is sometimes accompanied by the production of large volumes of molten rock. The total melt volume, however, is uncertain, because only part of it has erupted at the surface. Furthermore, the cause of the magmatism is still disputed—specifically, whether or not it is due to increased mantle temperatures. We recorded deep-penetration normal-incidence and wide-angle seismic profiles across the Faroe and Hatton Bank volcanic margins in the northeast Atlantic. Here we show that near the Faroe Islands, for every 1 km along strike, 360–400 km3 of basalt is extruded, while 540–600 km3 is intruded into the continent–ocean transition. We find that lower-crustal intrusions are focused mainly into a narrow zone approx50 km wide on the transition, although extruded basalts flow more than 100 km from the rift. Seismic profiles show that the melt is intruded into the lower crust as sills, which cross-cut the continental fabric, rather than as an 'underplate' of 100 per cent melt, as has often been assumed. Evidence from the measured seismic velocities and from igneous thicknesses are consistent with the dominant control on melt production being increased mantle temperatures, with no requirement for either significant active small-scale mantle convection under the rift or the presence of fertile mantle at the time of continental break-up, as has previously been suggested for the North Atlantic Ocean. |
format |
Article in Journal/Newspaper |
author |
White, R. S. Smith, L. K. Roberts, A. W. Christie, P. A. F. Kusznir, N. Team, iSimm |
author_facet |
White, R. S. Smith, L. K. Roberts, A. W. Christie, P. A. F. Kusznir, N. Team, iSimm |
author_sort |
White, R. S. |
title |
Lower-crustal intrusion on the north atlantic continental margin |
title_short |
Lower-crustal intrusion on the north atlantic continental margin |
title_full |
Lower-crustal intrusion on the north atlantic continental margin |
title_fullStr |
Lower-crustal intrusion on the north atlantic continental margin |
title_full_unstemmed |
Lower-crustal intrusion on the north atlantic continental margin |
title_sort |
lower-crustal intrusion on the north atlantic continental margin |
publishDate |
2008 |
url |
http://eprints.esc.cam.ac.uk/795/ http://eprints.esc.cam.ac.uk/795/1/White_Smith_Roberts_Christie_Kusznir_Nature452_%282008%29.pdf https://doi.org/10.1038/nature06687 |
long_lat |
ENVELOPE(-18.000,-18.000,58.583,58.583) |
geographic |
Faroe Islands Hatton Bank |
geographic_facet |
Faroe Islands Hatton Bank |
genre |
Faroe Islands North Atlantic Northeast Atlantic |
genre_facet |
Faroe Islands North Atlantic Northeast Atlantic |
op_relation |
http://eprints.esc.cam.ac.uk/795/1/White_Smith_Roberts_Christie_Kusznir_Nature452_%282008%29.pdf White, R. S. and Smith, L. K. and Roberts, A. W. and Christie, P. A. F. and Kusznir, N. and Team, iSimm (2008) Lower-crustal intrusion on the north atlantic continental margin. Nature, 452. pp. 460-464. DOI doi:10.1038 |
op_doi |
https://doi.org/10.1038/nature06687 |
container_title |
Nature |
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452 |
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7186 |
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460 |
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464 |
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