The ultra-slow spreading South West Indian Ridge (SWIR) near Marion Rise comprises segments of thin crust and abundant abyssal peridotites exposed near the ridge axis. As part of the “MARION” project we use highly siderophile elements and radiogenic isotopic ratios (187 Os/ 188 Os) to understand the melting/enrichment history of the mantle beneath SWIR. Thereby we test the hypothesis of buoyant depleted mantle beneath the SWIR that may represent Proterozoic melting residues recycled from Gondwana lithosphere (Zhou and Dick, 2013). The investigation will be a key role in the evaluation of a new geodynamic hypothesis on (ultra)slow-spreading rifting processes.

Contact: Prof. Harry Becker, Milena Waag