Iron (Fe) is a key factor limiting the biological uptake of CO2 in the Southern Ocean (SO) with large consequences on climate. Fe input by matter of glacial origin (MGO) has received far less attention than other Fe sources. MARGO will fill this gap by providing basic understanding of major processes controlling the nature and magnitude of MGO fluxes and their fate in the SO. The exceptional and multidisciplinary background of knowledge existing at Kerguelen pinpoints this region as an ideal site for the project. MARGO will be the first integrated investigation of the glacier-ocean continuum that will characterise the origin, fate and impact of MGO in the SO. MARGO relies on an ambitious multidisciplinary (glaciology, physics, geochemistry and microbiology) approach with a unique combination of data acquisition (on land and at sea), ice melting models and an ocean Lagrangian transport model to assess the dynamics of MGO delivery on different time scales and its impact in the SO