Deep magma oceans may have locked ferric iron into majorite on Earth and Mars‎

In rocky planets such as Earth and Mars, the oxidation state of the mantle is thought to strongly influence the melting temperature of mantle materials (i.e., magma generation), the composition of volcanic gases, and ultimately the evolution of surface environments. In particular, during the solidification of the "magma ocean," which is believed to have been widespread during the early stages of planetary formation, the oxidation state in which iron is incorporated into minerals is considered crucial for understanding subsequent mantle evolution.