Gas Mobility Patterns in Crystal Mush Analog Experiments

Abstract

Volatile movement through crystal mush, which controls the efficiency of gas escape, is poorly understood. Previous studies using 2-D (Hele-Shaw) analog experiments show that the geometry (finger, fracture) and efficiency of gas escape is controlled by particle concentration. I extend this approach by adding photoelastic particles to track formation and destruction of force chains. 2-D analog (Hele-Shaw) experiments using solid particles (photoelastic disks), fluid (corn syrup), and gas (nitrogen) are used to quantify the role of varying injected gas flux (1000 cm3/s to 10000 cm3/s) on crystal and melt migration patterns. Experiments can be classified by gas geometry into fingering, transition and fracture regime; recorded pressure and light intensity provide a proxy for particle stresses caused by the gas flux rate.