Figure F21. Plane-polarized (left) and cross-polarized (right) light photomicrographs showing variability of olivine and plagioclase replacement across different lithologies, Site U1415. Cpx = clinopyroxene, Chl = chlorite, Ol = olivine, Pl = plagioclase, Pr = prehnite, Serp = serpentine. A. Serpentinized olivine with a moderately well developed corona texture. Olivine is altered to chlorite along the edge of the grain in gabbro. The surrounding plagioclase is minimally fractured and slightly altered to prehnite along microfractures (Sample 345 U1415J-5R-1 [Piece 18, 138–141 cm]; Thin Section 38). B. Similar olivine alteration in the olivine gabbro in the Layered Series (Unit II), Hole U1415P. Coronitic textures are moderately well developed, but clinopyroxene and plagioclase are nearly fresh (Sample 345-U1415P-3R-1 [Piece 7, 113–115 cm]; Thin Section 96). C. Complete pseudomorphic replacement of plagioclase in association with strongly serpentinized olivine and prehnite veins in the Troctolitic Series (Unit III), Hole U1415P. Coronitic textures are absent from these relict olivine grains. (Sample 345 U1415P-22R-1 [Piece 7, 113–115 cm]; Thin Section 140).
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