Figure 20 | Table of Contents

Figure 19. Photomicrograph in cross-polarized light of a plagioclase phenocryst completely replaced by fine-grained illite (birefringent mineral) and possible halloysite (gray) (Sample 193 1188F-14Z-1, 102–105 cm; field of view = 0.7 mm).

Figure 20 | Table of Contents