Fig. 2: Surface and bulk composition of the fragmented clasts.
From: Nanoscale silicate melt textures determine volcanic ash surface chemistry
a The quotient of the elemental abundance at the nanoscale surface of experimental clasts measured by XPS with the average bulk composition measured by XRF. b Relative variation in the major phases between the bulk and the micron-scale surface of particles as measured by QEMSCAN. Positive values indicate phase enrichment at the surface. The average phase composition from all samples is shown in the inset. c The quotient of the nanoscale surface chemistry measured by XPS and the microscale surface chemistry calculated from EPMA and QEMSCAN data (calculated μm-scale surface). The coloured bars show ±2× standard error for all panels and mean absolute error is shown in the inset to (b). In the legend, RT and HT indicate room temperature or high temperature (850 °C), respectively, 10 and 30 refer to confining pressure (in MPa) in shock tube experiments, and the suffix letter refers to samples produced by crushing (C) or decompression fragmentation (F).
