Author name: Philipp Ruprecht

When magmas erupt at the surface, they may have undergone many changes since their inception. While olivine drives some of these changes through crystallization and fractionation, it also records the magma evolution via mineral chemistry and by trapping mineral and melt inclusions. Olivine is an effective recorder of intensive parameters, such as temperature and melt composition, and provides an outstanding petrological tool for constraining dynamic processes, such as ascent, mixing, and cooling. Olivine sheds light on magmatic puzzles that involve both mafic and more evolved magmas, with protracted and complex magmatic histories that often obscure earlier and deeper processes. This contribution summarizes the current state of how olivine helps reconstruct source-to-surface magma assembly through its chemistry, inclusions, and textures.

In some ways, olivine has driven the evolution of the Solar System and likely beyond. As one of the earliest-crystallizing silicate minerals, olivine controls the initial chemical evolution of planet-wide magma oceans and individual lava flows alike. In solid aggregate form, it controls and records deformation of the mantle and smaller-scale intrusive complexes. The components of its crystal structure are mobile at high temperatures and their migration can be used to explore the timing of magmatic events. During chemical weathering, these olivine crystals capture carbon dioxide from the atmosphere as secondary minerals are formed. All of these processes take place not only on Earth, but also on other planetary bodies, making olivine ideally suited to shed light on both primordial planet-building processes and current-day volcanism and surface processes.