The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean
The Azores—Biscay Rise is a roughly linear north-east—south-west trending feature rising 1500–3000m above its surroundings, which extends from about 4°N, 1°30′W towards the Azores. Its south-western termination is near 40°30′N, 21°30′W. About halfway along its length the Rise intersects the WNW-tren...
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fthighwire:oai:open-archive.highwire.org:gji:70/1/79 2023-05-15T17:22:40+02:00 The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean Whitmarsh, R. B. Ginzburg, A. Searle, R. C. 1982-07-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/70/1/79 https://doi.org/10.1111/j.1365-246X.1982.tb06393.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/70/1/79 http://dx.doi.org/10.1111/j.1365-246X.1982.tb06393.x Copyright (C) 1982, Oxford University Press Articles TEXT 1982 fthighwire https://doi.org/10.1111/j.1365-246X.1982.tb06393.x 2012-11-23T22:12:53Z The Azores—Biscay Rise is a roughly linear north-east—south-west trending feature rising 1500–3000m above its surroundings, which extends from about 4°N, 1°30′W towards the Azores. Its south-western termination is near 40°30′N, 21°30′W. About halfway along its length the Rise intersects the WNW-trending King's Trough. In 1978 a set of bathymetric, magnetic, gravity, GLORIA and seismic reflection and refraction data were obtained in the vicinity of the Rise. Together with earlier data these observations suggest that: (1) there has been no substantial post-emplacement tectonic activity, with the possible exception of the construction of some volcanic seamounts at the south-western end of the Rise, and (2) the Rise is underlain by a low-velocity (low-density) lower crust and is in isostatic equilibrium. The Rise can be convincingly shown to be the eastern half of a pair of ridges formed by abnormal crustal generation at the Mid-Atlantic Ridge crest between the times of anomalies 33 and 24 (76–56 Ma ago). The western counterpart of the Rise includes Gauss and Milne seamounts in the Newfoundland Basin. Magnetic anomaly 31 passes uninterruptedly across the Rise and therefore hypotheses that the northern part of the Rise was the site of a Cenozoic transform fault or subduction zone are not supported by our data. It is speculated that King's Trough was linked to the North Spanish Trough by an early Cenozoic east—west transform fault across the northern Iberia Abyssal Plain. This plate boundary became inactive about the middle of the Oligocene epoch. Text Newfoundland North East Atlantic HighWire Press (Stanford University) Mid-Atlantic Ridge Geophysical Journal International 70 1 79 107 |
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Articles Whitmarsh, R. B. Ginzburg, A. Searle, R. C. The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
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Articles |
description |
The Azores—Biscay Rise is a roughly linear north-east—south-west trending feature rising 1500–3000m above its surroundings, which extends from about 4°N, 1°30′W towards the Azores. Its south-western termination is near 40°30′N, 21°30′W. About halfway along its length the Rise intersects the WNW-trending King's Trough. In 1978 a set of bathymetric, magnetic, gravity, GLORIA and seismic reflection and refraction data were obtained in the vicinity of the Rise. Together with earlier data these observations suggest that: (1) there has been no substantial post-emplacement tectonic activity, with the possible exception of the construction of some volcanic seamounts at the south-western end of the Rise, and (2) the Rise is underlain by a low-velocity (low-density) lower crust and is in isostatic equilibrium. The Rise can be convincingly shown to be the eastern half of a pair of ridges formed by abnormal crustal generation at the Mid-Atlantic Ridge crest between the times of anomalies 33 and 24 (76–56 Ma ago). The western counterpart of the Rise includes Gauss and Milne seamounts in the Newfoundland Basin. Magnetic anomaly 31 passes uninterruptedly across the Rise and therefore hypotheses that the northern part of the Rise was the site of a Cenozoic transform fault or subduction zone are not supported by our data. It is speculated that King's Trough was linked to the North Spanish Trough by an early Cenozoic east—west transform fault across the northern Iberia Abyssal Plain. This plate boundary became inactive about the middle of the Oligocene epoch. |
format |
Text |
author |
Whitmarsh, R. B. Ginzburg, A. Searle, R. C. |
author_facet |
Whitmarsh, R. B. Ginzburg, A. Searle, R. C. |
author_sort |
Whitmarsh, R. B. |
title |
The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
title_short |
The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
title_full |
The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
title_fullStr |
The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
title_full_unstemmed |
The structure and origin of the Azores--Biscay Rise, North-east Atlantic Ocean |
title_sort |
structure and origin of the azores--biscay rise, north-east atlantic ocean |
publisher |
Oxford University Press |
publishDate |
1982 |
url |
http://gji.oxfordjournals.org/cgi/content/short/70/1/79 https://doi.org/10.1111/j.1365-246X.1982.tb06393.x |
geographic |
Mid-Atlantic Ridge |
geographic_facet |
Mid-Atlantic Ridge |
genre |
Newfoundland North East Atlantic |
genre_facet |
Newfoundland North East Atlantic |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/70/1/79 http://dx.doi.org/10.1111/j.1365-246X.1982.tb06393.x |
op_rights |
Copyright (C) 1982, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.1982.tb06393.x |
container_title |
Geophysical Journal International |
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70 |
container_issue |
1 |
container_start_page |
79 |
op_container_end_page |
107 |
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1766109475398221824 |