Figure F291. Orthopyroxene in basalts from the upper dike screen exhibiting varying degrees of replacement (Thin Section 100; Sample 312-1256D-227R-1, 23–28 cm; 1468.73 mbsf) (field of view = 0.6 mm). A. Granular, magnetite-free orthopyroxene surrounded (and replaced?) by chlorite + actinolite (plane-polarized light). Inclusion-rich plagioclase. Clinopyroxene + magnetite crystals. B. Same as A; cross-polarized light. C. Orthopyroxene partially replaced by actinolitic hornblende in the host rock, near an alteration halo (plane-polarized light). D. Same as C; cross-polarized light. E. Orthopyroxene completely replaced by actinolite in the host rock, near an alteration halo (plane-polarized light; FOV = 0.6 mm). F. Same as E; cross-polarized light.
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