Contribution a l'étude de la structure profonde du Banc de Crozet (Ocean Indien Austral) = Contribution to the study of the deep structure of the Crozet Bank (southern Indian Ocean)
Recq, M. (1989). Contribution a l'étude de la structure profonde du Banc de Crozet (Ocean Indien Austral) = Contribution to the study of the deep structure of the Crozet Bank (southern Indian Ocean). Mar. Geol. 88(1-2): 133-144
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, more
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| Keywords |
Earth sciences > Geology > Stratigraphy
Geological history
Properties > Sediment properties > Sediment structure
ISW, Crozet Bank; ISW, Crozet Basin [Marine Regions]
Marine/Coastal |
| Abstract |
The Crozet Bank, the eastern part of the Crozet Plateau (southern, Indian Ocean) is capped by two groups of islands that form the Crozet archipelago (Terres Australes et Antarctiques Francaises). A N-S trending 1500-m deep basin, the Indivat Basin, Cuts the Crozet Bank between the two island groups into two parts bearing different geological and volcanic characteristics: in the west, a 2.5-km thick basalt layer indicating well-developed volcanism, and in the east, a thin basalt layer and layer 3 just below a detrital layer. Such an arrangement may resemble that observed in oceanic structures where serpentinized peridotites have been cored just below the sediments. The interpretation of gravity anomalies on Ile aux Cochons and Ile de la Possession combined with marine geophysical data collected in the surrounding regions of the southern Indian Ocean shows that the crustal thickening observed below the Crozet Bank is caused by a > 12-km thick layer 3 which precludes local Airy-type compensation of the Crozet Bank. |
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