Figure F52. Photomicrograph showing remnant weakly aligned microlitic plagioclase in the groundmass of a bleached, sparsely vesicular volcanic rock. Clearly, alteration in this sample has not been strongly feldspar destructive (interval 193-1189A-3R-1, 6-10 cm, Unit 5, in plane-polarized light; width of view = 0.7 mm. Photomicrograph ID# 1189A

Figure F52. Photomicrograph showing remnant weakly aligned microlitic plagioclase in the groundmass of a bleached, sparsely vesicular volcanic rock. Clearly, alteration in this sample has not been strongly feldspar destructive (interval 193-1189A-3R-1, 6-10 cm, Unit 5, in plane-polarized light; width of view = 0.7 mm. Photomicrograph ID# 1189A_6; thin section 32).