Figure F33. Photomicrograph of textural variation from rim to interior of a second altered hyaloclastite breccia fragment in Unit V, Hole U1349A. Note the presence of brown Cr spinel (Thin Section 262; Sample 324-U1349A-16R-6, 71–73 cm). A, B. Pale brown altered glass formerly altered to palagonite, as evidenced by the remnant fibrous clay rims. The rock has only incipient plagioclase microlites in altered glass at the rim, but they are linked in a network within ~1 cm of the edge in B. C. Small bundles of sheaf spherulites around the microlites. D. Skeletal and dendritic longer crystals and individual acicular plagioclase, with well-developed radiating sheafs. E. Zones of different spherulitic crystallinity in the same part of the thin section. Transmitted light.
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