MUSH-OCEAN is a collaborative ANR-funded project aiming at improving our understanding of igneous processes at oceanic spreading centers. The coordinator is Lydéric France (IUF, CRPG-CNRS, Université de Lorraine), and other partners are ENS (Paris, France), ISTO (Orléans, France), LMV (Clermont-Ferrand, France). The approach is multi-disciplinary including petrography (textures, micro-structures…), geochemistry, experimental petrology, and numerical models.
The overarching goal of the MUSH-OCEAN proposal is to provide an integrated model for the accretion of oceanic crust. MUSH-OCEAN aims at making a breakthrough in our knowledge of oceanic magmatic systems by bringing new quantitative constraints on their differentiation and thermo-kinetic evolution using a combination of a numerical approach, cutting-edge analytical techniques and experimental models. The main objectives of MUSH-OCEAN are fourfold:
- Objective 1: provide a quantified characterization of melt-mush reactions (possibly the main process governing differentiation) that are likely widespread in oceanic mushy igneous reservoirs, and identify the petrographical and geochemical implications for plutonic cumulates and for the volcanic component.
- Objective 2: provide brand new constraints on the dynamics of the transition from magma to mush (mush locking), and melt segregation and migration in magma-mush systems. The corresponding results will provide quantitative constraints on the emplacement of magma reservoirs, together with unique quantitative data on the related microstructures.
- Objective 3: provide evidence for the widespread occurrence of an initial ephemeral magma stage (crystal-poor; mobilizable) and quantify the lifetime of eruptable/mobilizable magma bodies. This objective will help make the link with the rare geophysical observations of crystal-poor magma bodies at MOR.
- Objective 4: provide constraints on the lifetime and cooling rates of oceanic mushy reservoirs.
