Figure F38. Petrographic features of basalt of Unit 1 from Holes 1224A and 1224D. A. A small glomerocryst of intergrown euhedral clinopyroxene (pale brown) and tabular plagioclase (white) set in a dark, fine-grained basaltic matrix (Sample 200-1224A-4X-CC, 16-19 cm; plane-polarized light). B. Upper massive lava flow of Unit 1 (Sample 200-1224D-1R-2, 86-89 cm; plane-polarized light). Note the presence of scattered dark fine-grained basaltic material in between the larger equigranular crystals of clinopyroxene (pale brown) and plagioclase (white). C. Detail of skeletal titanomagnetite (rhombic cross section) and ilmenite (vertical grid) seen using reflected light in one of the dark interstitial patches. The round, yellow objects are globular sulfide that segregated immiscibly from interstitial differentiated basaltic melt (Sample 200-1224D-1R-2, 86-89 cm). D. A segregation vesicle half filled with devitrified basaltic melt (right side) (Sample 200-1224A-5X-1, 17-20 cm; plane-polarized light). Note the curving meniscus. The remainder of the vesicle is filled with secondary nontronite (green) and a pyrite crystal (bottom center). E. Detail of another segregation vesicle showing coarser-grained host basalt on the left, and a fine-grained intergrowth of acicular to spherulitic plagioclase, clinopyroxene, and trellislike titanomagnetite and ilmenite in the vesicle itself (Sample 200-1224D-1R-2, 86-89 cm; plane-polarized light).

Figure F38. Petrographic features of basalt of Unit 1 from Holes 1224A and 1224D. A. A small glomerocryst of intergrown euhedral clinopyroxene (pale brown) and tabular plagioclase (white) set in a dark, fine-grained basaltic matrix (Sample 200-1224A-4X-CC, 16-19 cm; plane-polarized light). B. Upper massive lava flow of Unit 1 (Sample 200-1224D-1R-2, 86-89 cm; plane-polarized light). Note the presence of scattered dark fine-grained basaltic material in between the larger equigranular crystals of clinopyroxene (pale brown) and plagioclase (white). C. Detail of skeletal titanomagnetite (rhombic cross section) and ilmenite (vertical grid) seen using reflected light in one of the dark interstitial patches. The round, yellow objects are globular sulfide that segregated immiscibly from interstitial differentiated basaltic melt (Sample 200-1224D-1R-2, 86-89 cm). D. A segregation vesicle half filled with devitrified basaltic melt (right side) (Sample 200-1224A-5X-1, 17-20 cm; plane-polarized light). Note the curving meniscus. The remainder of the vesicle is filled with secondary nontronite (green) and a pyrite crystal (bottom center). E. Detail of another segregation vesicle showing coarser-grained host basalt on the left, and a fine-grained intergrowth of acicular to spherulitic plagioclase, clinopyroxene, and trellislike titanomagnetite and ilmenite in the vesicle itself (Sample 200-1224D-1R-2, 86-89 cm; plane-polarized light).