Figure F19. Binocular microscope photomicrographs and close-up photographs of sparsely vesicular phyric basalt, Unit 2 (interval 336-U1383C-10R-1, 71–86 cm [Piece 15]). A. Half-round core photograph with a grayish-brown alteration halo surrounding a fresher gray interior. Red lines separate domains with different vesicle filling colors. B. Vesicle filling in the freshest gray groundmass composed mostly of bluish-green clay (celadonite). Field of view (FOV) = 1 cm. C. Composite vesicle filling at alteration halo boundary, with more abundant smectite and iddingsite assemblages. FOV = 1 cm. D. Vesicle filling further away from the freshest groundmass, with increased zeolite filling. FOV = 1 cm. E. Composite vesicle filling in the alteration halos, showing green clay and Fe oxyhydroxide fillings (note that Fe oxyhydroxide may either form the center or rims of the vesicles). FOV = 2 cm.
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