Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea
A 410 km long Ocean Bottom Seismometer profile spanning from the Bear Island, Barents Sea to oceanic crust formed along the Mohns Ridge has been modelled by use of ray-tracing with regard to observed P -waves. The northeastern part of the model represents typical continental crust, thinned from ca ....
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Oxford University Press
2011
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fthighwire:oai:open-archive.highwire.org:gji:184/2/541 2023-05-15T15:38:48+02:00 Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea Czuba, Wojciech Grad, Marek Mjelde, Rolf Guterch, Aleksander Libak, Audun Krüger, Frank Murai, Yoshio Schweitzer, Johannes IPY Project Group 2011-02-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/184/2/541 https://doi.org/10.1111/j.1365-246X.2010.04873.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/184/2/541 http://dx.doi.org/10.1111/j.1365-246X.2010.04873.x Copyright (C) 2011, Oxford University Press Geodynamics and Tectonics TEXT 2011 fthighwire https://doi.org/10.1111/j.1365-246X.2010.04873.x 2016-11-16T18:43:36Z A 410 km long Ocean Bottom Seismometer profile spanning from the Bear Island, Barents Sea to oceanic crust formed along the Mohns Ridge has been modelled by use of ray-tracing with regard to observed P -waves. The northeastern part of the model represents typical continental crust, thinned from ca . 30 km thickness beneath the Bear Island to ca . 13 km within the Continent—Ocean-Transition. Between the Hornsund FZ and the Knølegga Fault, a 3–4 km thick sedimentary basin, dominantly of Permian/Carboniferous age, is modelled beneath the ca . 1.5 km thick layer of volcanics (Vestbakken Volcanic Province). The P -wave velocity in the 3–4 km thick lowermost continental crust is significantly higher than normal ( ca . 7.5 km s−1). We interpret this layer as a mixture of mafic intrusions and continental crystalline blocks, dominantly related to the Paleocene-Early Eocene rifting event. The crystalline portion of the crust within the south-western part of the COT consists of a ca . 30 km wide and ca . 6 km thick high-velocity (7.3 km s−1) body. We interpret the body as a ridge of serpentinized peridotites. The magmatic portion of the ocean crust accreted along the Knipovich Ridge from continental break-up at ca . 35 Ma until ca . 20 Ma is 3–5 km thicker than normal. We interpret the increased magmatism as a passive response to the bending of this southernmost part of the Knipovich Ridge. The thickness of the magmatic portion of the crust formed along the Mohns Ridge at ca. 20 Ma decreases to ca. 3 km, which is normal for ultra slow spreading ridges. Text Barents Sea Bear Island Hornsund HighWire Press (Stanford University) Barents Sea Bear Island ENVELOPE(-67.250,-67.250,-68.151,-68.151) Hornsund ENVELOPE(15.865,15.865,76.979,76.979) Knipovich Ridge ENVELOPE(7.074,7.074,75.712,75.712) Vestbakken ENVELOPE(16.250,16.250,74.417,74.417) Geophysical Journal International 184 2 541 554 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Geodynamics and Tectonics |
spellingShingle |
Geodynamics and Tectonics Czuba, Wojciech Grad, Marek Mjelde, Rolf Guterch, Aleksander Libak, Audun Krüger, Frank Murai, Yoshio Schweitzer, Johannes IPY Project Group Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
topic_facet |
Geodynamics and Tectonics |
description |
A 410 km long Ocean Bottom Seismometer profile spanning from the Bear Island, Barents Sea to oceanic crust formed along the Mohns Ridge has been modelled by use of ray-tracing with regard to observed P -waves. The northeastern part of the model represents typical continental crust, thinned from ca . 30 km thickness beneath the Bear Island to ca . 13 km within the Continent—Ocean-Transition. Between the Hornsund FZ and the Knølegga Fault, a 3–4 km thick sedimentary basin, dominantly of Permian/Carboniferous age, is modelled beneath the ca . 1.5 km thick layer of volcanics (Vestbakken Volcanic Province). The P -wave velocity in the 3–4 km thick lowermost continental crust is significantly higher than normal ( ca . 7.5 km s−1). We interpret this layer as a mixture of mafic intrusions and continental crystalline blocks, dominantly related to the Paleocene-Early Eocene rifting event. The crystalline portion of the crust within the south-western part of the COT consists of a ca . 30 km wide and ca . 6 km thick high-velocity (7.3 km s−1) body. We interpret the body as a ridge of serpentinized peridotites. The magmatic portion of the ocean crust accreted along the Knipovich Ridge from continental break-up at ca . 35 Ma until ca . 20 Ma is 3–5 km thicker than normal. We interpret the increased magmatism as a passive response to the bending of this southernmost part of the Knipovich Ridge. The thickness of the magmatic portion of the crust formed along the Mohns Ridge at ca. 20 Ma decreases to ca. 3 km, which is normal for ultra slow spreading ridges. |
format |
Text |
author |
Czuba, Wojciech Grad, Marek Mjelde, Rolf Guterch, Aleksander Libak, Audun Krüger, Frank Murai, Yoshio Schweitzer, Johannes IPY Project Group |
author_facet |
Czuba, Wojciech Grad, Marek Mjelde, Rolf Guterch, Aleksander Libak, Audun Krüger, Frank Murai, Yoshio Schweitzer, Johannes IPY Project Group |
author_sort |
Czuba, Wojciech |
title |
Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
title_short |
Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
title_full |
Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
title_fullStr |
Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
title_full_unstemmed |
Continent--ocean-transition across a trans-tensional margin segment: off Bear Island, Barents Sea |
title_sort |
continent--ocean-transition across a trans-tensional margin segment: off bear island, barents sea |
publisher |
Oxford University Press |
publishDate |
2011 |
url |
http://gji.oxfordjournals.org/cgi/content/short/184/2/541 https://doi.org/10.1111/j.1365-246X.2010.04873.x |
long_lat |
ENVELOPE(-67.250,-67.250,-68.151,-68.151) ENVELOPE(15.865,15.865,76.979,76.979) ENVELOPE(7.074,7.074,75.712,75.712) ENVELOPE(16.250,16.250,74.417,74.417) |
geographic |
Barents Sea Bear Island Hornsund Knipovich Ridge Vestbakken |
geographic_facet |
Barents Sea Bear Island Hornsund Knipovich Ridge Vestbakken |
genre |
Barents Sea Bear Island Hornsund |
genre_facet |
Barents Sea Bear Island Hornsund |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/184/2/541 http://dx.doi.org/10.1111/j.1365-246X.2010.04873.x |
op_rights |
Copyright (C) 2011, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.2010.04873.x |
container_title |
Geophysical Journal International |
container_volume |
184 |
container_issue |
2 |
container_start_page |
541 |
op_container_end_page |
554 |
_version_ |
1766370138805764096 |