Figure F18. Photomicrographs of diabase showing subophytic texture with light plagioclase crystals encased in larger crystals of clinopyroxene and olivine (Sample 198-1213B-31R-3, 73-75 cm). Darker areas include opaque minerals and minor (altered) glassy groundmass. The upper view is in plane-polarized light, and the lower view is with nicols crossed.

Figure F18. Photomicrographs of diabase showing subophytic texture with light plagioclase crystals encased in larger crystals of clinopyroxene and olivine (Sample 198-1213B-31R-3, 73-75 cm). Darker areas include opaque minerals and minor (altered) glassy groundmass. The upper view is in plane-polarized light, and the lower view is with nicols crossed.