Figure F52. Photomicrograph of a section from finely laminated Unit 18 showing weakly developed alignment of plagioclase microlites and a single phenocryst. Silicification is expressed as patches of quartz masking alignment of microlites in the groundmass of the rock. Apparent high relief of plagioclase is a manufacturing artifact) (interval 193-1188A-16R-2, 40-43 cm, Unit 18, in plane-polarized light; width of view = 1.4 mm. Photomicrograph ID# 1188A

Figure F52. Photomicrograph of a section from finely laminated Unit 18 showing weakly developed alignment of plagioclase microlites and a single phenocryst. Silicification is expressed as patches of quartz masking alignment of microlites in the groundmass of the rock. Apparent high relief of plagioclase is a manufacturing artifact) (interval 193-1188A-16R-2, 40-43 cm, Unit 18, in plane-polarized light; width of view = 1.4 mm. Photomicrograph ID# 1188A_77; thin section 19).