Aurore Sibrant

The influence of plume-ridge interactions on the formation, evolution and rupture of oceanic plateau

PostDoctoral Fellow: Dr Aurore Sibrant
Scientific Sponsors: Dr Marcia Maia (LGO)
LabexMER Research Axis: Axis 4: Sediment transfer : source to sink, and mud to mantle

The formation of ocean plateau is one of the major characteristics resulting from the interaction between an ocean ridge and a mantle plume. However, the conditions necessary for the formation of these plateaux, and then their evolution, remain unclear after almost four decades of ocean exploration and numerical modelling. The aim of this project is to quantify the role of intrinsic ridge parameters (spreading rate, elastic thickness of the lithosphere, absolute migration of the ridge relative to the plume- and the mantle plume (vigour, volume of the plume and material emitted, periodicity of volcanism) on the formation or not of the oceanic plateau.

We focus our study on several key oceanic plateau such as Iceland, Skatsky, Galapagos, the foundation plateau, St. Paul Amsterdam and the Agulhas plateau, which together offer a wide range of spreading rate (from (de 16 à 91 km/Myr), plume vigor (between 0.4 x 10⁶ to 3.3 x 10⁶ g/s) and migration rate (from 22 to 55 mm/yr), as well as recent and old plateaus. This characterization will be based on the study of bathymetric and morphological data, gravimetric anomalies, reconstruction of tectonic movements and laboratory experiments.