Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean
Geochemistry, Geophysics, Geosystems, v. 4, n. 9, p. 1071, 2003. http://dx.doi.org/10.1029/2003GC000535 International audience Microcontinents appear to commonly form on young continental margins close to hot spots, butdifficulties in understanding their geology and evolution have inhibited assessme...
Published in: | Geochemistry, Geophysics, Geosystems |
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Main Authors: | , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2003
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Online Access: | https://hal.archives-ouvertes.fr/hal-00406983 https://hal.archives-ouvertes.fr/hal-00406983/document https://hal.archives-ouvertes.fr/hal-00406983/file/Borissova_et_al-2003-Geochemistry,_Geophysics,_Geosystems.pdf https://doi.org/10.1029/2003GC000535 |
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[SDU]Sciences of the Universe [physics] |
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[SDU]Sciences of the Universe [physics] Borissova, Irina Coffin, Millard F. Charvis, Philippe Operto, Stéphane Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
Geochemistry, Geophysics, Geosystems, v. 4, n. 9, p. 1071, 2003. http://dx.doi.org/10.1029/2003GC000535 International audience Microcontinents appear to commonly form on young continental margins close to hot spots, butdifficulties in understanding their geology and evolution have inhibited assessment of their globaldistribution and significance. Thick volcanic accumulations in areas affected by hot spot magmatismonly complicate the issue. Elan Bank, a large western salient of the Kerguelen Plateau, is amicrocontinent that originally lay between India and Antarctica in Gondwana. Recent regional platetectonic reconstructions suggest that during Gondwana breakup, Elan Bank and India initially separatedfrom Antarctica, and Elan Bank became isolated in the Southern Ocean via a ridge jump to the northbetween Elan Bank and India. In Albian time (108 Ma), voluminous magmatism attributed to theKerguelen 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 Bankallow us to gain the first insight into the feature’s integrated crustal structure and geological evolutionand the adjacent continent-ocean transition zone. Our analysis shows that Elan Bank’s crust is at least16 km thick. The upper igneous crust consists of a 2–3 km thick layer with seismic velocities rangingfrom 4.4 to 5.9 km/s that can be interpreted as the result of accumulation of lava flows originating fromthe Kerguelen hot spot. Seismic velocities at the base of the crust are as low as 6.6 km/s, which isconsistent with a fragment of thinned continental crust 14 km thick. A high velocity body, located atdepths of 5 to 10 km, could be interpreted as plutonic rocks emplaced during the major regionalmagmatic episode. On the basis of deep seismic reflection data, we interpret extensional structuresbeneath the volcanic flows. In Albian time, when the area was affected by the Kerguelen hot spot,volcaniclastic material and lava ... |
author2 |
Geoscience Australia Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO) Institute for Geophysics, Jackson School of Geosciences University of Texas at Austin Austin Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) Géoazur (GEOAZUR 7329) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ) |
format |
Article in Journal/Newspaper |
author |
Borissova, Irina Coffin, Millard F. Charvis, Philippe Operto, Stéphane |
author_facet |
Borissova, Irina Coffin, Millard F. Charvis, Philippe Operto, Stéphane |
author_sort |
Borissova, Irina |
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 |
publisher |
HAL CCSD |
publishDate |
2003 |
url |
https://hal.archives-ouvertes.fr/hal-00406983 https://hal.archives-ouvertes.fr/hal-00406983/document https://hal.archives-ouvertes.fr/hal-00406983/file/Borissova_et_al-2003-Geochemistry,_Geophysics,_Geosystems.pdf https://doi.org/10.1029/2003GC000535 |
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ENVELOPE(67.000,67.000,-56.750,-56.750) |
geographic |
Elan Bank Indian Kerguelen Southern Ocean |
geographic_facet |
Elan Bank Indian Kerguelen Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_source |
ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://hal.archives-ouvertes.fr/hal-00406983 Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2003, 4 (9), 16 p. ⟨10.1029/2003GC000535⟩ |
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info:eu-repo/semantics/OpenAccess |
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https://doi.org/10.1029/2003GC000535 |
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Geochemistry, Geophysics, Geosystems |
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ftunivnantes:oai:HAL:hal-00406983v1 2023-05-15T13:39:34+02:00 Structure and development of a microcontinent: Elan Bank in the southern Indian Ocean Borissova, Irina Coffin, Millard F. Charvis, Philippe Operto, Stéphane Geoscience Australia Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO) Institute for Geophysics, Jackson School of Geosciences University of Texas at Austin Austin Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) Géoazur (GEOAZUR 7329) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ) 2003 https://hal.archives-ouvertes.fr/hal-00406983 https://hal.archives-ouvertes.fr/hal-00406983/document https://hal.archives-ouvertes.fr/hal-00406983/file/Borissova_et_al-2003-Geochemistry,_Geophysics,_Geosystems.pdf https://doi.org/10.1029/2003GC000535 en eng HAL CCSD AGU and the Geochemical Society info:eu-repo/semantics/altIdentifier/doi/10.1029/2003GC000535 hal-00406983 https://hal.archives-ouvertes.fr/hal-00406983 https://hal.archives-ouvertes.fr/hal-00406983/document https://hal.archives-ouvertes.fr/hal-00406983/file/Borissova_et_al-2003-Geochemistry,_Geophysics,_Geosystems.pdf doi:10.1029/2003GC000535 info:eu-repo/semantics/OpenAccess ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://hal.archives-ouvertes.fr/hal-00406983 Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2003, 4 (9), 16 p. ⟨10.1029/2003GC000535⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2003 ftunivnantes https://doi.org/10.1029/2003GC000535 2022-08-10T06:55:32Z Geochemistry, Geophysics, Geosystems, v. 4, n. 9, p. 1071, 2003. http://dx.doi.org/10.1029/2003GC000535 International audience Microcontinents appear to commonly form on young continental margins close to hot spots, butdifficulties in understanding their geology and evolution have inhibited assessment of their globaldistribution and significance. Thick volcanic accumulations in areas affected by hot spot magmatismonly complicate the issue. Elan Bank, a large western salient of the Kerguelen Plateau, is amicrocontinent that originally lay between India and Antarctica in Gondwana. Recent regional platetectonic reconstructions suggest that during Gondwana breakup, Elan Bank and India initially separatedfrom Antarctica, and Elan Bank became isolated in the Southern Ocean via a ridge jump to the northbetween Elan Bank and India. In Albian time (108 Ma), voluminous magmatism attributed to theKerguelen 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 Bankallow us to gain the first insight into the feature’s integrated crustal structure and geological evolutionand the adjacent continent-ocean transition zone. Our analysis shows that Elan Bank’s crust is at least16 km thick. The upper igneous crust consists of a 2–3 km thick layer with seismic velocities rangingfrom 4.4 to 5.9 km/s that can be interpreted as the result of accumulation of lava flows originating fromthe Kerguelen hot spot. Seismic velocities at the base of the crust are as low as 6.6 km/s, which isconsistent with a fragment of thinned continental crust 14 km thick. A high velocity body, located atdepths of 5 to 10 km, could be interpreted as plutonic rocks emplaced during the major regionalmagmatic episode. On the basis of deep seismic reflection data, we interpret extensional structuresbeneath the volcanic flows. In Albian time, when the area was affected by the Kerguelen hot spot,volcaniclastic material and lava ... Article in Journal/Newspaper Antarc* Antarctica Southern Ocean Université de Nantes: HAL-UNIV-NANTES Elan Bank ENVELOPE(67.000,67.000,-56.750,-56.750) Indian Kerguelen Southern Ocean Geochemistry, Geophysics, Geosystems 4 9 n/a n/a |