Figure F6. Aphyric basalt with blotchy alteration texture from Unit 2 (pillow lava) (Section 336-U1382A-4R-1). A. Close-up photograph of cryptocrystalline groundmass with variolitic domains (Section 4R-1, 70–76 cm [Piece 9]). B. Thin section photomicrograph showing three domains separated by red lines: (1) cryptocrystalline groundmass with rare varioles, (2) variolitic part in center with numerous varioles, and (3) microcrystalline part with faint variolitic texture (Section 4R-1, 76–81 cm [Piece 10]). Olivine microphenocryst contents are uniform. Thin section = 25 mm wide; plane polarization.
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