Figure F20. A. Photomicrograph (in plane-polarized light) of the boundary between a glassy pillow margin (center right) and dolomitic sediment (extreme lower right) (Unit 1) in Sample 183-1140-26R-1 (Piece 2A, 84-86 cm). The inner part of the pillow's glassy margin (upper left) is fresh and contains olivine phenocrysts and plagioclase microlites, whereas the outermost glassy margin (center right) is aphyric and locally altered to brown clay. A set of carbonate veins (white) crosscuts or fills in open spaces in the pillow margin. B. Photomicrograph (in plane-polarized light) of the boundary between foraminifer-bearing dolomite (central area) and the glassy margin of a basaltic pillow lava (upper left) (Unit 1) in Sample 183-1140-26R-1 (Piece 2A, 84-86 cm). The outermost glassy margin is locally altered to brown clay; carbonate veins (white) run parallel to the boundary in this area.