Melt-driven planetary evolution

Silicate Melts play a dominant role in the evolution of rocky planets, shaping the planet's compositional trajectory through every phase of its lifetime. Magmas and lavas act as primary agents of chemical transport and evolution, a direct consequence of their high reactivities and mobilities (which arise from their atomic-scale structures and dominate their physical properties). Magmatic evolution is primarily responsible for the great diversity of rock types throughout terrestrial planets, determining how even highly similar mantle compositions can yield the wide variety of rock types seen throughout the solar system. Simultaneously, the thermodynamics of multi-phase melting and crystallization is largely responsible for the structures of rocky planet interiors. Additionally, the primitive outgassed atmospheres of rocky planets are controlled by the chemical thermodynamics of silicate melts, a key insight for predicting and interpreting the atmospheric compositions of rocky exoplanets.

In this talk, I will present thermodynamic modeling tools and simulation studies that are the focus of my work as a PI and primary developer of the ENKI project (www.enki-portal.org, supported by NSF and NASA). We will discuss an array of modeling tools that are being used to understand many of the major stages of rocky planet formation and evolution. These tools build upon thermochemical models of oxide & silicate minerals and melts, together with models for gaseous species and aqueous fluids. All of these modeling tools are open-source (see gitlab.com/ENKI-portal) and built on simplified Jupyter notebook interfaces, making them accessible to the planetary & geo-science communities. We will discuss a variety of rocky planet applications including the formation of their interiors (in terms of cores and magma oceans) as well as the evolution of their surfaces (covering crustal and surface volcanism as well as atmospheric outgassing). Finally, we will discuss ongoing efforts to dramatically improve the accuracy & scope of these modeling tools through the development of new thermochemical liquid models (exoMELTS) focused on capturing the effects of composition and pressure on silicate melting, with a specific aim toward describing the expanded diversity of planetary possibilities outside our solar system.