Figure F91. Brittle microstructures in cross-polarized transmitted light. Scale bars are 2 mm. A. Felsic vein crosscutting an undeformed igneous texture. The plagioclase in the veins is euhedral to subhedral and zoned. Sample 176-735B-172R-3 (Piece 2A, 70-76 cm). B. Thin amphibole vein (shown by the arrows) crosscutting large, slightly deformed plagioclase grains. Sample 176-735B-95R-3 (Piece 1C, 24-29 cm). C. Two calcite veins (nearly horizontal in the photo). The upper vein (1) may be a fault; it is filled with small, equigranular crystals. The lower vein (2) displays a crack-seal structure. Sample 176-735B-132R-1 (Piece 11A, 66-70 cm). D. Cataclasite, with a calcite matrix and angular clasts with a large range in grain size. Sample 176-735B-91R-3 (Piece 1D, 92-95 cm).