Figure F117. A. Cut surface of breccia associated with basalt affected by low-temperature hydrothermal alteration. Basalt clasts exhibit mixed brown + black alteration halos along their margins and are cemented by quartz + iron oxyhydroxide and saponite (black) (interval 206-1256D-57R-2, 71-79 cm). B. Close-up photograph of breccia associated with low-temperature hydrothermal alteration of basalt. Basalt clasts exhibit mixed brown + black alteration halos along their margins and are cemented by quartz + iron oxyhydroxide and saponite (black) (interval 206-1256D-57R-1, 0-12 cm).

Figure F117. A. Cut surface of breccia associated with basalt affected by low-temperature hydrothermal alteration. Basalt clasts exhibit mixed brown + black alteration halos along their margins and are cemented by quartz + iron oxyhydroxide and saponite (black) (interval 206-1256D-57R-2, 71-79 cm). B. Close-up photograph of breccia associated with low-temperature hydrothermal alteration of basalt. Basalt clasts exhibit mixed brown + black alteration halos along their margins and are cemented by quartz + iron oxyhydroxide and saponite (black) (interval 206-1256D-57R-1, 0-12 cm).