Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean
Microcontinents appear to commonly form on young continental margins close to hot spots, but difficulties in understanding their geology and evolution have inhibited assessment of their global distribution and significance. Thick volcanic accumulations in areas affected by hot spot magmatism only co...
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ftsouthampton:oai:eprints.soton.ac.uk:52440 2023-07-30T03:59:25+02:00 Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean Borissova, I. Coffin, M.F. Charvis, P. Operto, S. 2003 https://eprints.soton.ac.uk/52440/ http://www.agu.org/pubs/crossref/2003/2003GC000535.shtml unknown Borissova, I., Coffin, M.F., Charvis, P. and Operto, S. (2003) Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean. Geochemistry, Geophysics, Geosystems, 4 (9), art.1071. (doi:10.1029/2003GC000535 <http://dx.doi.org/10.1029/2003GC000535>). Article PeerReviewed 2003 ftsouthampton https://doi.org/10.1029/2003GC000535 2023-07-09T20:56:06Z Microcontinents appear to commonly form on young continental margins close to hot spots, but difficulties in understanding their geology and evolution have inhibited assessment of their global distribution and significance. Thick volcanic accumulations in areas affected by hot spot magmatism only complicate the issue. Elan Bank, a large western salient of the Kerguelen Plateau, is a microcontinent that originally lay between India and Antarctica in Gondwana. Recent regional plate tectonic reconstructions suggest that during Gondwana breakup, Elan Bank and India initially separated from Antarctica, and Elan Bank became isolated in the Southern Ocean via a ridge jump to the north between Elan Bank and India. In Albian time (?108 Ma), voluminous magmatism attributed to the Kerguelen hot spot overprinted and radically altered the original microcontinent and its surroundings. Recent ODP investigations, deep seismic reflection data, and a wide-angle seismic line on Elan Bank allow us to gain the first insight into the feature's integrated crustal structure and geological evolution and the adjacent continent-ocean transition zone. Our analysis shows that Elan Bank's crust is at least 16 km thick. The upper igneous crust consists of a 2–3 km thick layer with seismic velocities ranging from 4.4 to 5.9 km/s that can be interpreted as the result of accumulation of lava flows originating from the Kerguelen hot spot. Seismic velocities at the base of the crust are as low as 6.6 km/s, which is consistent with a fragment of thinned continental crust ?14 km thick. A high velocity body, located at depths of 5 to 10 km, could be interpreted as plutonic rocks emplaced during the major regional magmatic episode. On the basis of deep seismic reflection data, we interpret extensional structures beneath the volcanic flows. In Albian time, when the area was affected by the Kerguelen hot spot, volcaniclastic material and lava flows accumulated in faulted grabens and basins both on the bank and within the continent-ocean transition zone ... Article in Journal/Newspaper Antarc* Antarctica Southern Ocean University of Southampton: e-Prints Soton Southern Ocean Kerguelen Indian Elan Bank ENVELOPE(67.000,67.000,-56.750,-56.750) Geochemistry, Geophysics, Geosystems 4 9 n/a n/a |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
unknown |
description |
Microcontinents appear to commonly form on young continental margins close to hot spots, but difficulties in understanding their geology and evolution have inhibited assessment of their global distribution and significance. Thick volcanic accumulations in areas affected by hot spot magmatism only complicate the issue. Elan Bank, a large western salient of the Kerguelen Plateau, is a microcontinent that originally lay between India and Antarctica in Gondwana. Recent regional plate tectonic reconstructions suggest that during Gondwana breakup, Elan Bank and India initially separated from Antarctica, and Elan Bank became isolated in the Southern Ocean via a ridge jump to the north between Elan Bank and India. In Albian time (?108 Ma), voluminous magmatism attributed to the Kerguelen hot spot overprinted and radically altered the original microcontinent and its surroundings. Recent ODP investigations, deep seismic reflection data, and a wide-angle seismic line on Elan Bank allow us to gain the first insight into the feature's integrated crustal structure and geological evolution and the adjacent continent-ocean transition zone. Our analysis shows that Elan Bank's crust is at least 16 km thick. The upper igneous crust consists of a 2–3 km thick layer with seismic velocities ranging from 4.4 to 5.9 km/s that can be interpreted as the result of accumulation of lava flows originating from the Kerguelen hot spot. Seismic velocities at the base of the crust are as low as 6.6 km/s, which is consistent with a fragment of thinned continental crust ?14 km thick. A high velocity body, located at depths of 5 to 10 km, could be interpreted as plutonic rocks emplaced during the major regional magmatic episode. On the basis of deep seismic reflection data, we interpret extensional structures beneath the volcanic flows. In Albian time, when the area was affected by the Kerguelen hot spot, volcaniclastic material and lava flows accumulated in faulted grabens and basins both on the bank and within the continent-ocean transition zone ... |
format |
Article in Journal/Newspaper |
author |
Borissova, I. Coffin, M.F. Charvis, P. Operto, S. |
spellingShingle |
Borissova, I. Coffin, M.F. Charvis, P. Operto, S. Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
author_facet |
Borissova, I. Coffin, M.F. Charvis, P. Operto, S. |
author_sort |
Borissova, I. |
title |
Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
title_short |
Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
title_full |
Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
title_fullStr |
Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
title_full_unstemmed |
Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
title_sort |
structure and development of a microcontinent: elan bank in the southern indian ocean |
publishDate |
2003 |
url |
https://eprints.soton.ac.uk/52440/ http://www.agu.org/pubs/crossref/2003/2003GC000535.shtml |
long_lat |
ENVELOPE(67.000,67.000,-56.750,-56.750) |
geographic |
Southern Ocean Kerguelen Indian Elan Bank |
geographic_facet |
Southern Ocean Kerguelen Indian Elan Bank |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_relation |
Borissova, I., Coffin, M.F., Charvis, P. and Operto, S. (2003) Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean. Geochemistry, Geophysics, Geosystems, 4 (9), art.1071. (doi:10.1029/2003GC000535 <http://dx.doi.org/10.1029/2003GC000535>). |
op_doi |
https://doi.org/10.1029/2003GC000535 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
4 |
container_issue |
9 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1772810240809500672 |