Figure F50. A spherulite in a yellow-brown halo in Sample 192-1185B-4R-1 (Piece 18, 142-144 cm). The brown staining resulting from the olivine alteration enhances the fibroradial texture of the plagioclase and pyroxene. Elongate olivine crystals randomly scattered in the subvariolitic groundmass surrounding the spherulites are totally replaced by smectite and Fe oxyhydroxide. One skeletal olivine phenocryst replaced by the same secondary minerals can be observed (bottom center) (overall alteration = 3%-5%; field of view = 5.5 mm; plane-polarized light; photomicrograph ID# 1185B

Figure F50. A spherulite in a yellow-brown halo in Sample 192-1185B-4R-1 (Piece 18, 142-144 cm). The brown staining resulting from the olivine alteration enhances the fibroradial texture of the plagioclase and pyroxene. Elongate olivine crystals randomly scattered in the subvariolitic groundmass surrounding the spherulites are totally replaced by smectite and Fe oxyhydroxide. One skeletal olivine phenocryst replaced by the same secondary minerals can be observed (bottom center) (overall alteration = 3%-5%; field of view = 5.5 mm; plane-polarized light; photomicrograph ID# 1185B_218).