Figure F12. Photomicrographs showing a euhedral, doubly terminated quartz crystal growing into pore space. Also adjoining the pore space are abundant crystals of plagioclase with lesser proportions of oxides and amphibole (on the left side of the pore) (Sample 209-1272A-4R-1, 87–90 cm). A. Plane-polarized light: blue filter/blue + dark gray filter; field of view = 2.75 mm; image 1272A_001. B. Cross-polarized light: blue filter; field of view = 2.75 mm; image 1272A

Figure F12. Photomicrographs showing a euhedral, doubly terminated quartz crystal growing into pore space. Also adjoining the pore space are abundant crystals of plagioclase with lesser proportions of oxides and amphibole (on the left side of the pore) (Sample 209-1272A-4R-1, 87–90 cm). A. Plane-polarized light: blue filter/blue + dark gray filter; field of view = 2.75 mm; image 1272A_001. B. Cross-polarized light: blue filter; field of view = 2.75 mm; image 1272A_002.