Figure F16. Photomicrographs of basalt exhibiting a sparsely phyric texture (Sample 198-123B-31R-1, 7-10 cm). Phenocrysts of plagioclase and pyroxene are in a devitrified groundmass with radiating clusters of microlites. Hollow-appearing plagioclase microlites in the center of the view are likely a product of partial alteration or resorption. The upper view is in plane-polarized light, and the lower view is with nicols crossed.

Figure F16. Photomicrographs of basalt exhibiting a sparsely phyric texture (Sample 198-1213B-31R-1, 7-10 cm). Phenocrysts of plagioclase and pyroxene are in a devitrified groundmass with radiating clusters of microlites. Hollow-appearing plagioclase microlites in the center of the view are likely a product of partial alteration or resorption. The upper view is in plane-polarized light, and the lower view is with nicols crossed.