Origin of continental components in Indian Ocean basalts: Evidence from Elan Bank (Kerguelen Plateau, ODP Leg 183, Site 1137)

Basalts forming the floor of the Indian Ocean are geochemically distinct fr om those of the Atlantic and Pacific Oceans. These differences have been at tributed to a deeply recycled continental component or to widespread disper sion of plume-type mantle within the Indian Ocean asthenosphere. The discov ery of Proterozoic continental crustal rocks within the uppermost basaltic basement of Elan Bank, part of the Kerguelen Plateau, shows instead that di rect shallow-level contamination of basaltic magmas by isolated continental crust fragments may have produced the anomalous isotopic ratios of some In dian Ocean basalts.