Figure F29. Thin-section photomicrograph of a silicified unit without anhydrite veining (Unit 28) showing quartz ± pyrite amygdules in a fine-grained quartz-illite groundmass. Amygdules are <1 mm long, and elongate examples are preferentially oriented (interval 193-1188F-1Z-3, 86-89 cm; width of view = 2.75 mm. Photomicrograph ID# 1188F

Figure F29. Thin-section photomicrograph of a silicified unit without anhydrite veining (Unit 28) showing quartz ± pyrite amygdules in a fine-grained quartz-illite groundmass. Amygdules are <1 mm long, and elongate examples are preferentially oriented (interval 193-1188F-1Z-3, 86-89 cm; width of view = 2.75 mm. Photomicrograph ID# 1188F_12; thin section 61).