The rheology of crustal mushes is a crucial parameter controlling melt segregation and magma flow. However, the relations between mush dynamics and crystal size and shape distribution remain poorly understood because of the complexity of melt‐crystal and crystal‐crystal interactions. We performed analog experiments to characterize the mechanisms that control pore space reduction associated with repacking. Three suspensions of monodisperse particles with different geometries and aspect ratios (1:1, 2:1, 4:1) in a viscous fluid were tested. Our results show that particle aspect ratios strongly control the melt extraction processes. We identify two competing mechanisms that enable melt extraction at grain scale. The first mechanism leads to continuous deformation and melt extraction and is associated with “diffuse” frictional dissipation between neighboring particles. The second is stochastic, localized, and nearly instantaneous and is associated with the development and destruction of force chains percolating through the granular assembly.

Nearly all of Greenland's bedrock geology is inaccessible because it is covered by the Greenland Ice Sheet. Therefore, geophysical investigations are especially important in furthering our understanding of Greenland's subglacial lithospheric structure. Greenland is a region of interest as its lithosphere contains cratonic material and records the history of Archean, Proterozoic, and Paleozoic orogenies and could provide insight into the history of the Iceland plume (e.g., Henriksen et al., 2009). The majority of Greenland is Precambrian and has been modified by multiple tectonic (orogenic and rifting) events (e.g., Henriksen et al., 2009). Of particular note is the Trans-Hudson Orogeny, which was a widespread set of plate collisions that helped to build Laurentia around 1.8 Ga (e.g., St-Onge et al., 2009). Orogenic belts from this event can be found across North America; in Greenland, this includes the Rinkian and Nagssugtoqidian belts that bound major crustal blocks (e.g.

Several models of lunar formation that have recently gained momentum in the planetary science community involve, to an extent, the giant impact theory (e.g., the terrestrial synestia model of Lock et al. (2018)). In this giant impact theory, the Moon is thought to have been formed from the coalescence of debris from a collision between an impactor and a proto-Earth (Canup, 2004), leading to the formation of a lunar magmatic ocean and the large-scale degassing of the Moon (Lucey et al., 2006). The depletion of hydrogen (e.g., in the form of OH/H 2 O, hereafter referred to simply as "water" or H 2 O) in volcanic samples returned from Luna and Apollo missions seemed to support this, but a growing body of research now suggests that the lunar mantle, or at least some parts of the lunar mantle, may not be as severely depleted in water as previously thought (