Figure F41. Photomicrograph in plane-polarized light of basalt at the top of basement. Aphyric to sparsely plagioclase phyric basalt, cryptocrystalline to microcrystalline groundmass, which is highly altered forming clay minerals (Sample 191-1179D-10R-1 [Piece 1, 44-46 cm]) (see "Site 1179 Thin Sections").