Figure F56. Cataclastic zone in gabbro (between arrows labeled CC [cataclasite]) truncating all earlier structures (Thin Section 29; Sample 345-U1415J-3R-1, 11–13 cm [Piece 4]; under crossed polars). The zone contains broken angular fragments of plagioclase (Pl; pale gray) and clinopyroxene (Cpx; yellow) that apparently do not react with the fine-grained chlorite (Chl) cement. Other fractures break and locally displace grains above and below this zone of microbreccia. Northeast-trending bands of fibrous chlorite (F Chl) crosscut intergrowths of amphibole and chlorite (Am + Chl) that probably replaced magmatic olivine. Also present is amphibole that may have replaced ophitic clinopyroxene at a much higher temperature than the other alterations shown.
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