Carbon in mantle plumes and the carbonatite-LIP association

The spatio-temporal association between Large Igneous Provinces (LIPs) and carbonatites (igneous rocks containing more than 50% of carbonate minerals) poses key questions about the physical processes leading to the eruption of small volumes of carbonatites before the main-phase LIPs magmatism. Models that invoke partial melting of a carbonate-metasomatized lithosphere heated by the plume rely on a shaky physical assumption, namely that diffused heat reaches the lithosphere before buoyant melts. Here we depart from existing models in several ways: First, we consider that the plume, not the lithosphere, is the source of carbon. Second, we take into account the ionic nature of carbonate melts. Third, our numerical simulations provide a fluid dynamically consistent evolution of plume-lithosphere system.