Anomalous heat flow near the Crozet Plateau and mantle convection

Abstract A heat flow study has been performed near the Crozet Plateau (southern Indian Ocean), where the geoid and bathymetry are anomalously high with respect to the nearby deep ocean basins. Data collected on 67 Ma old oceanic crust agree with simple plate model predictions at the stations furthest removed from the plateau. Heat flow values increase significantly towards the centre of the feature, suggesting a thermal origin for this uplift. The ratio of geoid to bathymetry confirms that simple crustal thickening with Airy local compensation cannot explain the observations. The data are compatible with a model of dynamic convective support of the plateau by an underlying thermal plume in the earth's mantle.