Fig. 2: Relationships between minor element enrichments and lattice distortions.

Wavelength dispersive spectrometry (WDS) maps of P enrichment compared to electron backscatter diffraction (EBSD) maps (scale for both images shown on EBSD map). a–c Grains with internal lattice distortions (revealed by stripes of different colors in EBSD maps) have homogeneous concentrations of P in their cores (see WDS maps). Observed phosphorus enrichments in the rim of the crystal shown in c likely mark a period of rapid growth upon eruption. d Internal P enrichments are truncated against a subgrain boundary. WDS elemental maps are colored by the number of counts per pixel (in ImageJ). EBSD maps are colored using the inverse pole figure (IPF) key. A color reference direction is chosen such that the mean orientation of the central grain is colored white. The coloring denotes the misorientation axis and angle of each pixel relative to this reference direction. To emphasize small misorientations, the IPF key has been shrunk so that all the color variation is distributed across misorientation angles of 0–3°. For example, pixels misoriented about [010] by 3° from the mean orientation are colored dark blue (see the color scale, top right). Pixels misorientated by >3° are colored black. Light blue 3D olivine crystals are superimposed (using the MTEX crystalShape package) to allow visualization of the orientation of the three crystallographic axes ([100], [010], and [001], for space group Pbnm).