Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot?
Regional axial depths, mantle Bouguer anomaly values, geochemical proxies for the extent of partial melting and tomographic models along the Southwest Indian Ridge (SWIR) all concur in indicating the presence of thicker crust and hotter mantle between the Indomed and Gallieni transform faults (TFs;...
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Online Access: | http://hdl.handle.net/11577/154419 https://doi.org/10.1111/j.1365-246X.2009.04308.x http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2009.04308.x/full |
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ftunivpadovairis:oai:www.research.unipd.it:11577/154419 2024-04-21T07:51:25+00:00 Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? SAUTER D CANNAT C BEZOS A PATRIAT P HUMLER E. AND DEBAYLE E. MEYZEN, CHRISTINE MARIE Sauter, D Cannat, C Meyzen, CHRISTINE MARIE Bezos, A Patriat, P Humler, E. AND DEBAYLE E. 2009 ELETTRONICO http://hdl.handle.net/11577/154419 https://doi.org/10.1111/j.1365-246X.2009.04308.x http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2009.04308.x/full eng eng Blackwell Science Limited:PO Box 88, Oxford OX2 0NE United Kingdom:011 44 1865 776868, 011 44 1865 206038, EMAIL: journals.cs@blacksci.co.uk, INTERNET: http://www.blackwell-science.com, Fax: 011 44 1865 721205 info:eu-repo/semantics/altIdentifier/wos/WOS:000270652300002 volume:179 firstpage:687 lastpage:699 numberofpages:13 journal:GEOPHYSICAL JOURNAL INTERNATIONAL http://hdl.handle.net/11577/154419 doi:10.1111/j.1365-246X.2009.04308.x info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-70350396931 http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2009.04308.x/full info:eu-repo/semantics/article 2009 ftunivpadovairis https://doi.org/10.1111/j.1365-246X.2009.04308.x 2024-03-28T01:49:15Z Regional axial depths, mantle Bouguer anomaly values, geochemical proxies for the extent of partial melting and tomographic models along the Southwest Indian Ridge (SWIR) all concur in indicating the presence of thicker crust and hotter mantle between the Indomed and Gallieni transform faults (TFs; 46 degrees E and 52 degrees 20'E) relative to the neighbouring ridge sections. Accreted seafloor between these TFs over the past similar to 10 Myr is also locally much shallower (> 1000 m) and corresponds to thicker crust (> 1.7 km) than previously accreted seafloor along the same ridge region. Two large outward facing topographic gradients mark the outer edges of two anomalously shallow off-axis domains on the African and Antarctic plates. Their vertical relief (> 2000 m locally) and their geometry, parallel to the present-day axis along a > 210-km-long ridge section, suggest an extremely sudden and large event dated between similar to 8 (magnetic anomaly C4n) and similar to 11 Ma (magnetic anomaly C5n). Asymmetric spreading and small ridge jumps occur at the onset of the formation of the anomalously shallow off-axis domains, leading to a re-organization of the ridge segmentation. We interpret these anomalously shallow off-axis domains as the relicts of a volcanic plateau due to a sudden increase of the magma supply. This event of enhanced magmatism started in the central part of the ridge section and then propagated along axis to the east and probably also to the west. However, it did not cross the Gallieni and Indomed TFs suggesting that large offsets can curtail or even block along-axis melt flow. We propose that this melting anomaly may be ascribed to a regionally higher mantle temperature provided by mantle outpouring from the Crozet hotspot towards the SWIR. Article in Journal/Newspaper Antarc* Antarctic Padua Research Archive (IRIS - Università degli Studi di Padova) Geophysical Journal International 179 2 687 699 |
institution |
Open Polar |
collection |
Padua Research Archive (IRIS - Università degli Studi di Padova) |
op_collection_id |
ftunivpadovairis |
language |
English |
description |
Regional axial depths, mantle Bouguer anomaly values, geochemical proxies for the extent of partial melting and tomographic models along the Southwest Indian Ridge (SWIR) all concur in indicating the presence of thicker crust and hotter mantle between the Indomed and Gallieni transform faults (TFs; 46 degrees E and 52 degrees 20'E) relative to the neighbouring ridge sections. Accreted seafloor between these TFs over the past similar to 10 Myr is also locally much shallower (> 1000 m) and corresponds to thicker crust (> 1.7 km) than previously accreted seafloor along the same ridge region. Two large outward facing topographic gradients mark the outer edges of two anomalously shallow off-axis domains on the African and Antarctic plates. Their vertical relief (> 2000 m locally) and their geometry, parallel to the present-day axis along a > 210-km-long ridge section, suggest an extremely sudden and large event dated between similar to 8 (magnetic anomaly C4n) and similar to 11 Ma (magnetic anomaly C5n). Asymmetric spreading and small ridge jumps occur at the onset of the formation of the anomalously shallow off-axis domains, leading to a re-organization of the ridge segmentation. We interpret these anomalously shallow off-axis domains as the relicts of a volcanic plateau due to a sudden increase of the magma supply. This event of enhanced magmatism started in the central part of the ridge section and then propagated along axis to the east and probably also to the west. However, it did not cross the Gallieni and Indomed TFs suggesting that large offsets can curtail or even block along-axis melt flow. We propose that this melting anomaly may be ascribed to a regionally higher mantle temperature provided by mantle outpouring from the Crozet hotspot towards the SWIR. |
author2 |
Sauter, D Cannat, C Meyzen, CHRISTINE MARIE Bezos, A Patriat, P Humler, E. AND DEBAYLE E. |
format |
Article in Journal/Newspaper |
author |
SAUTER D CANNAT C BEZOS A PATRIAT P HUMLER E. AND DEBAYLE E. MEYZEN, CHRISTINE MARIE |
spellingShingle |
SAUTER D CANNAT C BEZOS A PATRIAT P HUMLER E. AND DEBAYLE E. MEYZEN, CHRISTINE MARIE Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
author_facet |
SAUTER D CANNAT C BEZOS A PATRIAT P HUMLER E. AND DEBAYLE E. MEYZEN, CHRISTINE MARIE |
author_sort |
SAUTER D |
title |
Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
title_short |
Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
title_full |
Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
title_fullStr |
Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
title_full_unstemmed |
Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: interaction with the Crozet hot-spot? |
title_sort |
propagation of a melting anomaly along the ultraslow southwest indian ridge between 46°e and 52°20'e: interaction with the crozet hot-spot? |
publisher |
Blackwell Science Limited:PO Box 88, Oxford OX2 0NE United Kingdom:011 44 1865 776868, 011 44 1865 206038, EMAIL: journals.cs@blacksci.co.uk, INTERNET: http://www.blackwell-science.com, Fax: 011 44 1865 721205 |
publishDate |
2009 |
url |
http://hdl.handle.net/11577/154419 https://doi.org/10.1111/j.1365-246X.2009.04308.x http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2009.04308.x/full |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000270652300002 volume:179 firstpage:687 lastpage:699 numberofpages:13 journal:GEOPHYSICAL JOURNAL INTERNATIONAL http://hdl.handle.net/11577/154419 doi:10.1111/j.1365-246X.2009.04308.x info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-70350396931 http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2009.04308.x/full |
op_doi |
https://doi.org/10.1111/j.1365-246X.2009.04308.x |
container_title |
Geophysical Journal International |
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179 |
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2 |
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687 |
op_container_end_page |
699 |
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