Figure F5. Moderately altered rhyodacite where remnants of the original groundmass are locally preserved as isolated xenolith-like domains with sharp, angular outlines in thin section (Sample 193-1191A-3R-1 [Piece 1, 0-9 cm] in plane-polarized light; width of view = 1.38 mm. Photomicrograph ID# 1191A

Figure F5. Moderately altered rhyodacite where remnants of the original groundmass are locally preserved as isolated xenolith-like domains with sharp, angular outlines in thin section (Sample 193-1191A-3R-1 [Piece 1, 0-9 cm] in plane-polarized light; width of view = 1.38 mm. Photomicrograph ID# 1191A_10; thin section 50).