Figure F57. Locally foliated cataclasite after olivine gabbro (Thin Section 79; Sample 345-U1415J-21R-1, 103–107 cm [Piece 14]). Fractured plagioclase (Pl) clasts partially replaced by secondary plagioclase (2Pl) dominate the northwest portion of the image and are set in a cataclastic matrix (CC1). A second cataclasite (southeast quadrant) is dominated by polycrystalline prehnite clasts in a cataclastic matrix (CC2) of prehnite and local chlorite. A band of chlorite trending east-northeast separates the two bands of cataclasite. Near the edges of the image chlorite is in random orientation (Chl-R), whereas the center of the image and along the margins of the cataclasite show strong east-northeast preferred orientation (white arrows), and in the center of the image these chlorite folia are intergrown with small lenses of epidote (Ep). The phyllonitic band (Ph) of chlorite was opened and a small vein of prehnite (Pr; yellow arrows) fills this opening. A. Plane-polarized light. B. Under crossed polars.
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