Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile
A P-wave velocity model along a 565-km-long profile across the Grand Banks-Newfoundland Basin rifted margin is presented. Continental crust ∼36 km thick beneath the Grand Banks is divided into upper (5.8-6.25 km s -1 ), middle (6.3-6.53 km s -1 ) and lower crust (6.77-6.9 km s -1 ), consistent with...
Published in: | Geophysical Journal International |
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Language: | English |
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2006
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Online Access: | https://curis.ku.dk/portal/da/publications/crustal-structure-across-the-grand-banksnewfoundland-basin-continental-margin--i-results-from-a-seismic-refraction-profile(817454ce-a364-430d-afe3-6b467edf940a).html https://doi.org/10.1111/j.1365-246X.2006.02988.x http://www.scopus.com/inward/record.url?scp=33749420405&partnerID=8YFLogxK |
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ftcopenhagenunip:oai:pure.atira.dk:publications/817454ce-a364-430d-afe3-6b467edf940a 2023-07-23T04:20:23+02:00 Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile Lau, K. W.Helen Louden, Keith E. Funck, Thomas Tucholke, Brian E. Holbrook, W. Steven Hopper, John R. Christian Larsen, Hans 2006-10 https://curis.ku.dk/portal/da/publications/crustal-structure-across-the-grand-banksnewfoundland-basin-continental-margin--i-results-from-a-seismic-refraction-profile(817454ce-a364-430d-afe3-6b467edf940a).html https://doi.org/10.1111/j.1365-246X.2006.02988.x http://www.scopus.com/inward/record.url?scp=33749420405&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess Lau , K W H , Louden , K E , Funck , T , Tucholke , B E , Holbrook , W S , Hopper , J R & Christian Larsen , H 2006 , ' Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile ' , Geophysical Journal International , vol. 167 , no. 1 , pp. 127-156 . https://doi.org/10.1111/j.1365-246X.2006.02988.x Continental margins Crustal structures Refraction seismology Rifted margins article 2006 ftcopenhagenunip https://doi.org/10.1111/j.1365-246X.2006.02988.x 2023-07-05T23:17:24Z A P-wave velocity model along a 565-km-long profile across the Grand Banks-Newfoundland Basin rifted margin is presented. Continental crust ∼36 km thick beneath the Grand Banks is divided into upper (5.8-6.25 km s -1 ), middle (6.3-6.53 km s -1 ) and lower crust (6.77-6.9 km s -1 ), consistent with velocity structure of Avalon zone Appalachian crust. Syn-rift sediment sequences 6-7 km thick occur in two primary layers within the Jeanne d'Arc and the Carson basins (∼3 km s -1 in upper layer; ∼5 km s -1 in lower layer). Abrupt crustal thinning (Moho dip ∼35°) beneath the Carson basin and more gradual thinning seaward forms a 170-km-wide zone of rifted continental crust. Within this zone, lower and middle continental crust thin preferentially seawards until they are completely removed, while very thin (<3 km) upper crust continues ∼60 km farther seawards. Adjacent to the continental crust, high-velocity gradients (0.5-1.5 s -1 ) define an 80-km-wide zone of transitional basement that can be interpreted as exhumed, serpentinized mantle or anomalously thin oceanic crust, based on its velocity model alone. We prefer the exhumed-mantle interpretation after considering the non-reflective character of the basement and the low amplitude of associated magnetic anomalies, which are atypical of oceanic crust. Beneath both the transitional basement and thin (<6 km) continental crust, a 200-km-wide zone with reduced mantle velocities (7.6-7.9 km s -1 ) is observed, which is interpreted as partially (<10 per cent) serpentinized mantle. Seawards of the transitional basement, 2- to 6-km-thick crust with layer 2 (4.5-6.3 km s -1 ) and layer 3 (6.3-7.2 km s -1 ) velocities is interpreted as oceanic crust. Comparison of our crustal model with profile IAM-9 across the Iberia Abyssal Plain on the conjugate Iberia margin suggests asymmetrical continental breakup in which a wider zone of extended continental crust has been left on the Newfoundland side. Article in Journal/Newspaper Newfoundland University of Copenhagen: Research Geophysical Journal International 167 1 127 156 |
institution |
Open Polar |
collection |
University of Copenhagen: Research |
op_collection_id |
ftcopenhagenunip |
language |
English |
topic |
Continental margins Crustal structures Refraction seismology Rifted margins |
spellingShingle |
Continental margins Crustal structures Refraction seismology Rifted margins Lau, K. W.Helen Louden, Keith E. Funck, Thomas Tucholke, Brian E. Holbrook, W. Steven Hopper, John R. Christian Larsen, Hans Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
topic_facet |
Continental margins Crustal structures Refraction seismology Rifted margins |
description |
A P-wave velocity model along a 565-km-long profile across the Grand Banks-Newfoundland Basin rifted margin is presented. Continental crust ∼36 km thick beneath the Grand Banks is divided into upper (5.8-6.25 km s -1 ), middle (6.3-6.53 km s -1 ) and lower crust (6.77-6.9 km s -1 ), consistent with velocity structure of Avalon zone Appalachian crust. Syn-rift sediment sequences 6-7 km thick occur in two primary layers within the Jeanne d'Arc and the Carson basins (∼3 km s -1 in upper layer; ∼5 km s -1 in lower layer). Abrupt crustal thinning (Moho dip ∼35°) beneath the Carson basin and more gradual thinning seaward forms a 170-km-wide zone of rifted continental crust. Within this zone, lower and middle continental crust thin preferentially seawards until they are completely removed, while very thin (<3 km) upper crust continues ∼60 km farther seawards. Adjacent to the continental crust, high-velocity gradients (0.5-1.5 s -1 ) define an 80-km-wide zone of transitional basement that can be interpreted as exhumed, serpentinized mantle or anomalously thin oceanic crust, based on its velocity model alone. We prefer the exhumed-mantle interpretation after considering the non-reflective character of the basement and the low amplitude of associated magnetic anomalies, which are atypical of oceanic crust. Beneath both the transitional basement and thin (<6 km) continental crust, a 200-km-wide zone with reduced mantle velocities (7.6-7.9 km s -1 ) is observed, which is interpreted as partially (<10 per cent) serpentinized mantle. Seawards of the transitional basement, 2- to 6-km-thick crust with layer 2 (4.5-6.3 km s -1 ) and layer 3 (6.3-7.2 km s -1 ) velocities is interpreted as oceanic crust. Comparison of our crustal model with profile IAM-9 across the Iberia Abyssal Plain on the conjugate Iberia margin suggests asymmetrical continental breakup in which a wider zone of extended continental crust has been left on the Newfoundland side. |
format |
Article in Journal/Newspaper |
author |
Lau, K. W.Helen Louden, Keith E. Funck, Thomas Tucholke, Brian E. Holbrook, W. Steven Hopper, John R. Christian Larsen, Hans |
author_facet |
Lau, K. W.Helen Louden, Keith E. Funck, Thomas Tucholke, Brian E. Holbrook, W. Steven Hopper, John R. Christian Larsen, Hans |
author_sort |
Lau, K. W.Helen |
title |
Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
title_short |
Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
title_full |
Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
title_fullStr |
Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
title_full_unstemmed |
Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile |
title_sort |
crustal structure across the grand banks-newfoundland basin continental margin - i. results from a seismic refraction profile |
publishDate |
2006 |
url |
https://curis.ku.dk/portal/da/publications/crustal-structure-across-the-grand-banksnewfoundland-basin-continental-margin--i-results-from-a-seismic-refraction-profile(817454ce-a364-430d-afe3-6b467edf940a).html https://doi.org/10.1111/j.1365-246X.2006.02988.x http://www.scopus.com/inward/record.url?scp=33749420405&partnerID=8YFLogxK |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Lau , K W H , Louden , K E , Funck , T , Tucholke , B E , Holbrook , W S , Hopper , J R & Christian Larsen , H 2006 , ' Crustal structure across the Grand Banks-Newfoundland Basin Continental Margin - I. Results from a seismic refraction profile ' , Geophysical Journal International , vol. 167 , no. 1 , pp. 127-156 . https://doi.org/10.1111/j.1365-246X.2006.02988.x |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1111/j.1365-246X.2006.02988.x |
container_title |
Geophysical Journal International |
container_volume |
167 |
container_issue |
1 |
container_start_page |
127 |
op_container_end_page |
156 |
_version_ |
1772184650616143872 |