To generate a self-sustained magnetic field on terrestrial planets, the convection of a metallic liquid outer core is necessary (Breuer, 2019). Liquid core convection may be driven by thermal buoyancy from superadiabatic heat flows (thermal dynamo) across the core-mantle boundary (CMB) or by compositional buoyancy from the exsolution of light elements (e.g., O, C, and Si) at the inner-core boundary (ICB) (chemical dynamo;

The Earth’s core formation mechanism determines the siderophile and light elements abundance in the Earth’s mantle and core. Previous studies suggest that the sink of massive liquid metal through a solid silicate mantle resulted in an unequilibrated core and the lower mantle. Here, we show that percolation can be an effective core formation mechanism in a convective mantle and modify the compositions of the lower mantle and the core through partial equilibration between them. This grain-scale metal flow has a high velocity to meet the time constraint of core formation. The Earth’s core could have been enriched with light elements, and the abundance of the moderately siderophile elements in the mantle could have been elevated to the current value during this process. The trapped core-forming melt in the mantle during the stress-induced percolation can also explain the highly siderophile element abundance in the Earth’s mantle.

Bridgmanite is the most abundant mineral in the Earth's lower mantle. Consequently, it should govern the structure, dynamics, and evolution of the lower mantle. Accordingly, it is important to have the best possible knowledge concerning its chemistry. The major component of bridgmanite is MgSiO 3 . However, it can incorporate Al 3+ , Fe 2+ , and Fe 3+ as secondary elements. Hence, the chemistry of bridgmanite needs to be investigated in the Mg-Fe-Al-Si-O system. Because it too challenging to determine the effect of each individual element on the bridgmanite chemistry when investigating this five-component system, we need to start by investigating bridgmanite in simple systems and then expand to more complex systems. Another essential strategy in our series of investigations is to uniquely control the bridgmanite chemistry via the coexisting phases based on the phase rule. Using these strategies, the phase relations of the MgO-Al 2 O 3 -SiO 2 , MgO-Fe 2 O 3 -SiO 2 , and MgO-FeAlO 3 -SiO 2 systems with specific coexisting phases as a function of pressure and temperature have been investigated in recent studies (