Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening

Seismic reflection and refraction data from the SE Greenland margin provide a detailed view of a volcanic rifted margin from Archean continental crust to near-to-average oceanic crust over a spatial scale of 400 km. The SIGMA III transect, located ∼600 km south of the Greenland-Iceland Ridge and the...

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Main Authors: Hopper, John R., Dahl-Jesnen, Trine, Holbrook, W. Steven, Larsen, Hans Christian, Lizarralde, Dan, Korenaga, Jun, Kent, Graham M., Kelemen, Peter B.
Format: Article in Journal/Newspaper
Language:English
Published: 2003
Subjects:
Online Access:https://curis.ku.dk/portal/da/publications/structure-of-the-se-greenland-margin-from-seismic-reflection-and-refraction-data(acadb279-6efe-42e9-92c6-0a8c1f99c1e5).html
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record_format openpolar
spelling ftcopenhagenunip:oai:pure.atira.dk:publications/acadb279-6efe-42e9-92c6-0a8c1f99c1e5 2024-02-27T08:41:03+00:00 Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening Hopper, John R. Dahl-Jesnen, Trine Holbrook, W. Steven Larsen, Hans Christian Lizarralde, Dan Korenaga, Jun Kent, Graham M. Kelemen, Peter B. 2003-05-10 https://curis.ku.dk/portal/da/publications/structure-of-the-se-greenland-margin-from-seismic-reflection-and-refraction-data(acadb279-6efe-42e9-92c6-0a8c1f99c1e5).html http://www.scopus.com/inward/record.url?scp=0041382666&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Hopper , J R , Dahl-Jesnen , T , Holbrook , W S , Larsen , H C , Lizarralde , D , Korenaga , J , Kent , G M & Kelemen , P B 2003 , ' Structure of the SE Greenland margin from seismic reflection and refraction data : Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening ' , Journal of Geophysical Research: Solid Earth , vol. 108 , no. 5 , pp. EPM 13-1 - 13-22 . Asymmetric spreading Continental breakup Greenland margin Mantle dynamics Volcanic rifted margin article 2003 ftcopenhagenunip 2024-02-01T00:30:28Z Seismic reflection and refraction data from the SE Greenland margin provide a detailed view of a volcanic rifted margin from Archean continental crust to near-to-average oceanic crust over a spatial scale of 400 km. The SIGMA III transect, located ∼600 km south of the Greenland-Iceland Ridge and the presumed track of the Iceland hot spot, shows that the continent-ocean transition is abrupt and only a small amount of crustal thinning occurred prior to final breakup. Initially, 18.3 km thick crust accreted to the margin and the productivity decreased through time until a steady state ridge system was established that produced 8-10 km thick crust. Changes in the morphology of the basaltic extrusives provide evidence for vertical motions of the ridge system, which was close to sea level for at least 1 m.y. of subaerial spreading despite a reduction in productivity from 17 to 13.5 km thick crust over this time interval. This could be explained if a small component of active upwelling associated with thermal buoyancy from a modest thermal anomaly provided dynamic support to the rift system. The thermal anomaly must be exhaustible, consistent with recent suggestions that plume material was emplaced into a preexisting lithospheric thin spot as a thin sheet. Exhaustion of the thin sheet led to rapid subsidence of the spreading system and a change from subaerial, to shallow marine, and finally to deep marine extrusion in ∼2 m.y. is shown by the morphological changes. In addition, comparison to the conjugate Hatton Bank shows a clear asymmetry in the early accretion history of North Atlantic oceanic crust. Nearly double the volume of material was emplaced on the Greenland margin compared to Hatton Bank and may indicate east directed ridge migration during initial opening. Article in Journal/Newspaper Greenland Iceland North Atlantic University of Copenhagen: Research Greenland Hatton Bank ENVELOPE(-18.000,-18.000,58.583,58.583)
institution Open Polar
collection University of Copenhagen: Research
op_collection_id ftcopenhagenunip
language English
topic Asymmetric spreading
Continental breakup
Greenland margin
Mantle dynamics
Volcanic rifted margin
spellingShingle Asymmetric spreading
Continental breakup
Greenland margin
Mantle dynamics
Volcanic rifted margin
Hopper, John R.
Dahl-Jesnen, Trine
Holbrook, W. Steven
Larsen, Hans Christian
Lizarralde, Dan
Korenaga, Jun
Kent, Graham M.
Kelemen, Peter B.
Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
topic_facet Asymmetric spreading
Continental breakup
Greenland margin
Mantle dynamics
Volcanic rifted margin
description Seismic reflection and refraction data from the SE Greenland margin provide a detailed view of a volcanic rifted margin from Archean continental crust to near-to-average oceanic crust over a spatial scale of 400 km. The SIGMA III transect, located ∼600 km south of the Greenland-Iceland Ridge and the presumed track of the Iceland hot spot, shows that the continent-ocean transition is abrupt and only a small amount of crustal thinning occurred prior to final breakup. Initially, 18.3 km thick crust accreted to the margin and the productivity decreased through time until a steady state ridge system was established that produced 8-10 km thick crust. Changes in the morphology of the basaltic extrusives provide evidence for vertical motions of the ridge system, which was close to sea level for at least 1 m.y. of subaerial spreading despite a reduction in productivity from 17 to 13.5 km thick crust over this time interval. This could be explained if a small component of active upwelling associated with thermal buoyancy from a modest thermal anomaly provided dynamic support to the rift system. The thermal anomaly must be exhaustible, consistent with recent suggestions that plume material was emplaced into a preexisting lithospheric thin spot as a thin sheet. Exhaustion of the thin sheet led to rapid subsidence of the spreading system and a change from subaerial, to shallow marine, and finally to deep marine extrusion in ∼2 m.y. is shown by the morphological changes. In addition, comparison to the conjugate Hatton Bank shows a clear asymmetry in the early accretion history of North Atlantic oceanic crust. Nearly double the volume of material was emplaced on the Greenland margin compared to Hatton Bank and may indicate east directed ridge migration during initial opening.
format Article in Journal/Newspaper
author Hopper, John R.
Dahl-Jesnen, Trine
Holbrook, W. Steven
Larsen, Hans Christian
Lizarralde, Dan
Korenaga, Jun
Kent, Graham M.
Kelemen, Peter B.
author_facet Hopper, John R.
Dahl-Jesnen, Trine
Holbrook, W. Steven
Larsen, Hans Christian
Lizarralde, Dan
Korenaga, Jun
Kent, Graham M.
Kelemen, Peter B.
author_sort Hopper, John R.
title Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
title_short Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
title_full Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
title_fullStr Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
title_full_unstemmed Structure of the SE Greenland margin from seismic reflection and refraction data:Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening
title_sort structure of the se greenland margin from seismic reflection and refraction data:implications for nascent spreading center subsidence and asymmetric crustal accretion during north atlantic opening
publishDate 2003
url https://curis.ku.dk/portal/da/publications/structure-of-the-se-greenland-margin-from-seismic-reflection-and-refraction-data(acadb279-6efe-42e9-92c6-0a8c1f99c1e5).html
http://www.scopus.com/inward/record.url?scp=0041382666&partnerID=8YFLogxK
long_lat ENVELOPE(-18.000,-18.000,58.583,58.583)
geographic Greenland
Hatton Bank
geographic_facet Greenland
Hatton Bank
genre Greenland
Iceland
North Atlantic
genre_facet Greenland
Iceland
North Atlantic
op_source Hopper , J R , Dahl-Jesnen , T , Holbrook , W S , Larsen , H C , Lizarralde , D , Korenaga , J , Kent , G M & Kelemen , P B 2003 , ' Structure of the SE Greenland margin from seismic reflection and refraction data : Implications for nascent spreading center subsidence and asymmetric crustal accretion during North Atlantic opening ' , Journal of Geophysical Research: Solid Earth , vol. 108 , no. 5 , pp. EPM 13-1 - 13-22 .
op_rights info:eu-repo/semantics/restrictedAccess
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