Figure F7. Half-round and whole-round core scanner images illustrating different kinds of alteration features, Unit 1 (interval 336-U1383C-4R-1, 93–111 cm). A. Grayish-brown alteration halos in sparsely phyric basalt with microcrystalline groundmass. Both subhorizontal and vertical veins are composed of micritic carbonate with minor smectite and iddingsite. B. Pervasively altered sparsely plagioclase-phyric basalt with microcrystalline groundmass (interval 336-U1383C-3R-3, 55–62 cm [Piece 10]). Groundmass contains microphenocrysts of plagioclase laths (<1 mm) and olivine (<0.3 mm) altered to iddingsite. Note the inclined irregular veinlet in the center, filled with dark green clay, and the larger carbonate (micritic) vein on the left.
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