Volcanisme de l'ı̂le aux Pingouins,archipel Crozet,témoin de l'hétérogénéité du manteau fertile au sud de l'océan IndienPenguins Island,Crozet archipelago,volcanic evidence for a heterogeneous mantle in the southern Indian Ocean |
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| Authors: | André Giret Sylvie Tourpin Sabine Marc Olivier Verdier Jean-Yves Cottin |
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| Institution: | 1. Laboratoire de géologie, CNRS–UMR 6524 « Magmas et volcans », faculté des sciences et techniques, université Jean-Monnet, 23, rue du Docteur-Paul-Michelon, 42023 Saint-Étienne cedex 2, France;2. Unicem, 3, rue Alfred-Roll, 75017 Paris, France |
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| Abstract: | Despite its small area (5.6 km2), the Penguins Island brings magmatic information concerning mantle geochemical heterogeneities in southwestern Indian Ocean. The volcanism that built the island was firstly associated with marine deposits, and secondly with aerial, giving then abundant volcanic breccias and lava flows. The rocks are weakly differentiated and result of magmatic fractionation from picritic to tephritic types. KAr ages are near 1.1 Ma. The magmatic source may be related to a HIMU reservoir or to EMI ± EMII ones, depending on the geochemical evidences that are taken into account. However, comparisons with the Marion Island, on the same oceanic plateau and far to the west, as well as with Kerguelen Islands, far to the east, suggest a very heterogeneous mantle source. To cite this article: A. Giret et al., C. R. Geoscience 334 (2002) 481–488. |
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| Keywords: | volcanism Indian Ocean Crozet mantle hot spot volcanisme océan Indien Crozet manteau point chaud Océanographie Géologie marine Oceanography Marine geology |
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