Figure F106. A. Close-up photograph of basalt with dark gray background alteration, crosscut by saponite veins with black alteration halos (interval 206-1256D-63R-1, 92-102 cm). B. Close-up photograph of a saponite vein with a <10-mm-wide black alteration halo, which has a pyrite front. This alteration halo is partly overprinted by the later, oblique mixed halo associated with the iron oxyhydroxide-bearing saponite vein (interval 206-1256D-28R-1, 115-126 cm).

Figure F106. A. Close-up photograph of basalt with dark gray background alteration, crosscut by saponite veins with black alteration halos (interval 206-1256D-63R-1, 92-102 cm). B. Close-up photograph of a saponite vein with a <10-mm-wide black alteration halo, which has a pyrite front. This alteration halo is partly overprinted by the later, oblique mixed halo associated with the iron oxyhydroxide-bearing saponite vein (interval 206-1256D-28R-1, 115-126 cm).