Figure F15. Photomicrographs showing reaction rims around olivine and spinel at a contact between dunite and gabbro. A, B. Symplectic intergrowths of spinel and alteration phases (possibly replacing plagioclase) around a spinel grain (Sample 209-1271B-7R-1, 26–29 cm) (plane-polarized light [PPL]: blue filter); (A) field of view [FOV] = 2.75 mm; image 1271B_033; (B) close up of symplectic intergrowth (FOV = 1.4 mm; image 1271B_034). C, D. Symplectic intergrowths of spinel, olivine, and an alteration phase at a contact between olivine and an alteration phase similar to the one forming the intergrowth (Sample 209-1271B-10R-1, 40–43 cm) (FOV = 0.7 mm); (C) PPL: blue + light gray + dark gray filters; image 1271B_022; (D) cross-polarized light [XPL]: blue filter; image 1271B_023. E, F. Symplectic intergrowths of spinel, olivine, and an alteration phase at an olivine/altered gabbro contact (Sample 209-1271B-10R-1, 40–43 cm) (FOV = 1.4 mm); (E) PPL: blue + light gray filters; image 1271B_015; (F) XPL: dark gray filter; image 1271B

Figure F15. Photomicrographs showing reaction rims around olivine and spinel at a contact between dunite and gabbro. A, B. Symplectic intergrowths of spinel and alteration phases (possibly replacing plagioclase) around a spinel grain (Sample 209-1271B-7R-1, 26–29 cm) (plane-polarized light [PPL]: blue filter); (A) field of view [FOV] = 2.75 mm; image 1271B_033; (B) close up of symplectic intergrowth (FOV = 1.4 mm; image 1271B_034). C, D. Symplectic intergrowths of spinel, olivine, and an alteration phase at a contact between olivine and an alteration phase similar to the one forming the intergrowth (Sample 209-1271B-10R-1, 40–43 cm) (FOV = 0.7 mm); (C) PPL: blue + light gray + dark gray filters; image 1271B_022; (D) cross-polarized light [XPL]: blue filter; image 1271B_023. E, F. Symplectic intergrowths of spinel, olivine, and an alteration phase at an olivine/altered gabbro contact (Sample 209-1271B-10R-1, 40–43 cm) (FOV = 1.4 mm); (E) PPL: blue + light gray filters; image 1271B_015; (F) XPL: dark gray filter; image 1271B_016.