Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data
Among the mantle hotspots present under oceanic areas, a large number are located on—or close to—active oceanic ridges. This is especially true in the slow-spreading Atlantic and Indian oceans. The recent availability of worldwide gravity grids and the increasing coverage of geochemical data sets al...
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fthighwire:oai:open-archive.highwire.org:gji:135/2/700 2023-05-15T15:45:56+02:00 Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data Goslin, Jean Thirot, Jean-Louis Noël, Olivier Francheteau, Jean 1998-11-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/135/2/700 https://doi.org/10.1046/j.1365-246X.1998.00609.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/135/2/700 http://dx.doi.org/10.1046/j.1365-246X.1998.00609.x Copyright (C) 1998, Oxford University Press Research Note TEXT 1998 fthighwire https://doi.org/10.1046/j.1365-246X.1998.00609.x 2015-02-28T22:00:50Z Among the mantle hotspots present under oceanic areas, a large number are located on—or close to—active oceanic ridges. This is especially true in the slow-spreading Atlantic and Indian oceans. The recent availability of worldwide gravity grids and the increasing coverage of geochemical data sets along active spreading centres allow a fruitful comparison of these data with global geoid and seismic tomography models, and allow one to study interactions between mantle plumes and active slow-spreading ridges. The observed correlations allow us to draw preliminary conclusions on the general links between surficial processes, which shape the detailed morphology of the ridge axes, and deeper processes, active in the upper mantle below the ridge axial domains as a whole. The interactions are first studied at the scale of the Atlantic (the Mid-Atlantic Ridge from Iceland to Bouvet Island) from the correlation between the zero-age free-air gravity anomaly, which reflects the zero-age depth of the ridge axis, and Sr isotopic ratios of ridge axis basalts. The study is then extended to a more global scale (the slow ridges from Iceland to the Gulf of Aden) by including geoid and upper-mantle tomography models. The interactions appear complex, ranging from the effect of large and very productive plumes, almost totally overprinting the long-wavelength segmentation pattern of the ridge, to that of weaker hotspots, barely marking some of the observables in the ridge axial domain. Intermediate cases are observed, in which hotspots of medium activity (or whose activity has gradually decreased) located at some distance from the ridge axis produce geophysical or geochemical signals whose variation along the axis can be correlated with the geometry of the plume head in the upper mantle. Such observations tend to preclude the use of a single hotspot/ridge interaction model and stress the need for additional observations in various plume/ridge configurations. Text Bouvet Island Iceland HighWire Press (Stanford University) Indian Mid-Atlantic Ridge Bouvet ENVELOPE(3.358,3.358,-54.422,-54.422) Bouvet Island ENVELOPE(3.358,3.358,-54.422,-54.422) Geophysical Journal International 135 2 700 710 |
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HighWire Press (Stanford University) |
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English |
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Research Note |
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Research Note Goslin, Jean Thirot, Jean-Louis Noël, Olivier Francheteau, Jean Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
topic_facet |
Research Note |
description |
Among the mantle hotspots present under oceanic areas, a large number are located on—or close to—active oceanic ridges. This is especially true in the slow-spreading Atlantic and Indian oceans. The recent availability of worldwide gravity grids and the increasing coverage of geochemical data sets along active spreading centres allow a fruitful comparison of these data with global geoid and seismic tomography models, and allow one to study interactions between mantle plumes and active slow-spreading ridges. The observed correlations allow us to draw preliminary conclusions on the general links between surficial processes, which shape the detailed morphology of the ridge axes, and deeper processes, active in the upper mantle below the ridge axial domains as a whole. The interactions are first studied at the scale of the Atlantic (the Mid-Atlantic Ridge from Iceland to Bouvet Island) from the correlation between the zero-age free-air gravity anomaly, which reflects the zero-age depth of the ridge axis, and Sr isotopic ratios of ridge axis basalts. The study is then extended to a more global scale (the slow ridges from Iceland to the Gulf of Aden) by including geoid and upper-mantle tomography models. The interactions appear complex, ranging from the effect of large and very productive plumes, almost totally overprinting the long-wavelength segmentation pattern of the ridge, to that of weaker hotspots, barely marking some of the observables in the ridge axial domain. Intermediate cases are observed, in which hotspots of medium activity (or whose activity has gradually decreased) located at some distance from the ridge axis produce geophysical or geochemical signals whose variation along the axis can be correlated with the geometry of the plume head in the upper mantle. Such observations tend to preclude the use of a single hotspot/ridge interaction model and stress the need for additional observations in various plume/ridge configurations. |
format |
Text |
author |
Goslin, Jean Thirot, Jean-Louis Noël, Olivier Francheteau, Jean |
author_facet |
Goslin, Jean Thirot, Jean-Louis Noël, Olivier Francheteau, Jean |
author_sort |
Goslin, Jean |
title |
Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
title_short |
Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
title_full |
Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
title_fullStr |
Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
title_full_unstemmed |
Slow-ridge/hotspot interactions from global gravity, seismic tomography and 87Sr/86Sr isotope data |
title_sort |
slow-ridge/hotspot interactions from global gravity, seismic tomography and 87sr/86sr isotope data |
publisher |
Oxford University Press |
publishDate |
1998 |
url |
http://gji.oxfordjournals.org/cgi/content/short/135/2/700 https://doi.org/10.1046/j.1365-246X.1998.00609.x |
long_lat |
ENVELOPE(3.358,3.358,-54.422,-54.422) ENVELOPE(3.358,3.358,-54.422,-54.422) |
geographic |
Indian Mid-Atlantic Ridge Bouvet Bouvet Island |
geographic_facet |
Indian Mid-Atlantic Ridge Bouvet Bouvet Island |
genre |
Bouvet Island Iceland |
genre_facet |
Bouvet Island Iceland |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/135/2/700 http://dx.doi.org/10.1046/j.1365-246X.1998.00609.x |
op_rights |
Copyright (C) 1998, Oxford University Press |
op_doi |
https://doi.org/10.1046/j.1365-246X.1998.00609.x |
container_title |
Geophysical Journal International |
container_volume |
135 |
container_issue |
2 |
container_start_page |
700 |
op_container_end_page |
710 |
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1766380599635869696 |