Figure F35. Thin section photomicrographs emphasizing details of glass shard transformation and characteristics of palagonite development in altered hyaloclastite, Hole U1348A. A. Extensive spheroid development at the edge of an altered glass grain (Thin Section 155; Sample 324-U1348A-13R-1, 43–47 cm). B–D. Thin Section 157 (Sample 324-U1348A-14R-1, 18–20 cm). B. Bubble-wall outline of an altered shard rimmed with fibropalagonite and with a completely replaced interior. C. Altered stretched glass with "ribs," having the same alteration features. D. Irregular hyaloclastite glass shard with closely spaced interior spheroids. E. Outlines of angular glass shards rimmed with fibropalagonite and interiors replaced by calcite and surrounded by radiating zeolite that defines an original porosity of ~30% (Thin Section 169; Sample 324-U1348A-18R-3, 11–15 cm). Transmitted light.
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