Figure F39. Photomicrographs illustrating crosscutting relationships between different generations of veins in Hole 1268A. A. Late pyrite-hematite vein cuts and transposes previous veins of chrysotile—now replaced by talc and bastite (Sample 209-1268A-13R-1, 68–71 cm) (cross-polarized light: blue + gray filters; field of view = 2.75 mm; image 1268_021). B. Bastite cut by a massive talc vein and locally replaced along cleavage by talc. The massive talc vein also crosscuts chrysotile veins—now pseudomorphed to talc and an earlier talc-pyrite vein (Sample 209-1268A-12R-3, 71–74 cm) (cross-polarized light: blue + light gray filters; field of view = 2.75 mm; image 1268A_019). C, D. Boundary between serpentine background alteration and overprinting talc alteration. An early chrysotile vein is replaced by late, nonpseudomorphic massive talc alteration, becoming a "ghost vein" in the area of talc alteration (to the lower right) (Sample 209-1268A-14R-3, 3–5 cm) (field of view = 2.75 mm); (C) cross-polarized light: blue filter; image 1268A_027; (D) plane-polarized light: blue + light gray filters; image 1268A

Figure F39. Photomicrographs illustrating crosscutting relationships between different generations of veins in Hole 1268A. A. Late pyrite-hematite vein cuts and transposes previous veins of chrysotile—now replaced by talc and bastite (Sample 209-1268A-13R-1, 68–71 cm) (cross-polarized light: blue + gray filters; field of view = 2.75 mm; image 1268_021). B. Bastite cut by a massive talc vein and locally replaced along cleavage by talc. The massive talc vein also crosscuts chrysotile veins—now pseudomorphed to talc and an earlier talc-pyrite vein (Sample 209-1268A-12R-3, 71–74 cm) (cross-polarized light: blue + light gray filters; field of view = 2.75 mm; image 1268A_019). C, D. Boundary between serpentine background alteration and overprinting talc alteration. An early chrysotile vein is replaced by late, nonpseudomorphic massive talc alteration, becoming a "ghost vein" in the area of talc alteration (to the lower right) (Sample 209-1268A-14R-3, 3–5 cm) (field of view = 2.75 mm); (C) cross-polarized light: blue filter; image 1268A_027; (D) plane-polarized light: blue + light gray filters; image 1268A_028.