Figure 1.

Characteristics of isolated volcanic ash and pure-phase componentry. (A) Cumulative particle size distributions of volcanic ash sample MRA5/6/99 and componentry samples. (B) Particle size distribution and SEM image of volcanic ash sample MRA5/6/99 (×4.00k magnification). All particle size data are the average of three runs. (C) False-color backscatter SEM image of ash in cross section (×10k magnification) evidencing the heterogeneous distribution of predominant phases: cristobalite, feldspar, and volcanic glass. Electron dispersive X-ray spectroscopy was employed for mineral identification. Images were collected at 8.0 kV and a 14.5 mm working distance.