Provenance of Proterozoic garnet-biotite gneiss recovered from Elan Bank, Kerguelen Plateau, southern Indian Ocean

At Elan Bank of the Kerguelen Plateau in the southeast Indian Ocean, Leg 18 3 of the Ocean Drilling Program recovered clasts of garnet-biotite gneiss i n a fluvial conglomerate intercalated with basalt flows. U-Pb and Ph-Ph dat es of zircons and monazites in these clasts and an overlying sandstone rang e from 534 to 2547 Ma, which is much older than the surrounding Indian Ocea n seafloor. These dates show that old continental crust resides in the shal low crust of the oceanic Kerguelen Plateau and that the breakup of Gondwana dispersed continental fragments into the nascent Indian Ocean lithosphere.