Figure F62. Photomicrograph of a typical silicified unit from the lower sequence of Hole 1188F. Remnant corroded plagioclase microcrysts show a trachytic alignment and are hosted in a fine-grained alteration assemblage of quartz and illite. The coarsely crystalline quartz fills original vesicles. (interval 193-1188F-37Z-2, 18-20 cm, Unit 57, in cross-polarized light; width of view = 5.5 mm. Photomicrograph ID# 1188F_107; thin section 100).