Chimborazo volcanic debris avalanche deposit in Riobamba, Ecuador

Quarry of the ~40,000-year-old Chimborazo volcanic debris avalanche deposit in Riobamba, Ecuador. Inset from left to right: Photoelastic disks from Vanel et al. 1999 showing the distribution of forces in the form of force chains, discrete element method simulation rendering of spherical particles in a conical pile, and a rendering of the distribution of force chains in the simulated pile.