Depth to Curie temperature or bottom of the magnetic sources in the volcanic zone of la Réunion hot spot

Abstract : We present an innovative study to generalize Curie Point Depth (CPD) determinations at the scale of oceanic volcanic islands, an approach which has previously focused largely on continental areas. In order to determine the validity of this technique in oceanic environments, we first tested the approach on sets of sea-floor-spreading anomalies. Assuming that magnetic anomalies are concentrated within the oceanic crust and uppermost mantle, the Curie depth should deepen as oceanic lithosphere increases in age and thickness away from spreading centers. The calculated depths to the magnetic bottom are in agreement with this general pattern. On the basis of this test, we then applied the method to La Réunion Island and surrounding oceanic lithosphere. The calculated extent of magnetic sources lies at depths between 10 and 30 km and exhibits a complex topography, presumably caused by a combination of various magmatic and tectonic lithospheric structures. These calculations indicate that magnetic sources extend well below the crust-mantle interface at this location. To the first order, the bottom of the magnetic surface shallows beneath Réunion and Mauritius Islands due to the thermal effect of the hot spot, and deepens away from La Réunion edifice. On the scale of the Mascarene Basin, several discontinuities in the CPD correlate well with major fracture zones.
Type de document :
Article dans une revue
Journal of Volcanology and Geothermal Research, Elsevier, 2016, 324, pp.169 - 178. 〈10.1016/j.jvolgeores.2016.06.005〉
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https://hal-clermont-univ.archives-ouvertes.fr/hal-01637158
Contributeur : Sylvaine Jouhannel <>
Soumis le : vendredi 17 novembre 2017 - 13:39:13
Dernière modification le : mercredi 30 mai 2018 - 01:17:58

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Lydie-Sarah Gailler, Jean-François Lénat, Richard J. Blakely. Depth to Curie temperature or bottom of the magnetic sources in the volcanic zone of la Réunion hot spot. Journal of Volcanology and Geothermal Research, Elsevier, 2016, 324, pp.169 - 178. 〈10.1016/j.jvolgeores.2016.06.005〉. 〈hal-01637158〉

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