Figure F18. A-D. Photomicrographs showing olivine gabbro in which olivine and plagioclase are in textural equilibrium (Sample 209-1271B-18R-1, 20–23 cm) (cross-polarized light: blue filter). (A) Olivine, plagioclase, and clinopyroxene assemblage (field of view [FOV] = 5.5 mm; image 1271BB_068). (B) Grains of olivine included in partially altered plagioclase (FOV = 5.5 mm; image 1271B_067). (C) Grains of olivine included in poikilitic clinopyroxene (FOV = 5.5 mm; image 1271B_040). (D) Close-up of image C showing plagioclase laths and olivine (FOV = 1.4 mm; image 1271B_041). E, F. Photomicrographs showing troctolite in which olivine and plagioclase are separated by amphibole (Sample 209-1271B-16R-1, 24–27 cm) (plane-polarized light: blue + light gray filters). (E) Olivine grains within amphibole assemblages. Clusters of plagioclase form patches within the amphiboles (FOV = 5.5 mm; image 1271B_083). (F) Higher magnification image of E showing the three major mineral phases, plagioclase (P), amphibole (A), and olivine (O) (FOV = 1.4 mm; image 1271B

Figure F18. A-D. Photomicrographs showing olivine gabbro in which olivine and plagioclase are in textural equilibrium (Sample 209-1271B-18R-1, 20–23 cm) (cross-polarized light: blue filter). (A) Olivine, plagioclase, and clinopyroxene assemblage (field of view [FOV] = 5.5 mm; image 1271BB_068). (B) Grains of olivine included in partially altered plagioclase (FOV = 5.5 mm; image 1271B_067). (C) Grains of olivine included in poikilitic clinopyroxene (FOV = 5.5 mm; image 1271B_040). (D) Close-up of image C showing plagioclase laths and olivine (FOV = 1.4 mm; image 1271B_041). E, F. Photomicrographs showing troctolite in which olivine and plagioclase are separated by amphibole (Sample 209-1271B-16R-1, 24–27 cm) (plane-polarized light: blue + light gray filters). (E) Olivine grains within amphibole assemblages. Clusters of plagioclase form patches within the amphiboles (FOV = 5.5 mm; image 1271B_083). (F) Higher magnification image of E showing the three major mineral phases, plagioclase (P), amphibole (A), and olivine (O) (FOV = 1.4 mm; image 1271B_036).