Figure F14. Remnant flow banding in volcanic fragments of hydrothermal breccia units is defined by alternating linear to wavy light gray and gray green domains in hand specimen (cf. Figs. F6, , F8, , F9, ). In thin section, these bands correspond to light brown and brown to black groundmass domains (Sample 193-1189A-3R-1 [Piece 10, 59-63 cm]). A. A flow-banded volcanic fragment has been fractured by quartz-anhydrite veins. Microcrystalline flow bands are light brown and brown to black and gently folded (Field of view = 5.5 mm × 4.3 mm. Photomicrograph ID# 1189A_81). B. Enlarged view of area shown in (A) with a white box. Under high magnification, and using the condenser, very fine grained minerals with low birefringence (silica polymorphs, sulfate, and/or zeolite?) can be recognized in the light bands. Dark bands contain abundant, black cryptocrystalline material. The contacts between light and dark bands are weakly defined and irregular (Field of view = 0.54 mm × 0.69 mm. Photomicrograph ID# 1189A

Figure F14. Remnant flow banding in volcanic fragments of hydrothermal breccia units is defined by alternating linear to wavy light gray and gray green domains in hand specimen (cf. Figs. F6, F8, F9). In thin section, these bands correspond to light brown and brown to black groundmass domains (Sample 193-1189A-3R-1 [Piece 10, 59-63 cm]). A. A flow-banded volcanic fragment has been fractured by quartz-anhydrite veins. Microcrystalline flow bands are light brown and brown to black and gently folded (Field of view = 5.5 mm × 4.3 mm. Photomicrograph ID# 1189A_81). B. Enlarged view of area shown in (A) with a white box. Under high magnification, and using the condenser, very fine grained minerals with low birefringence (silica polymorphs, sulfate, and/or zeolite?) can be recognized in the light bands. Dark bands contain abundant, black cryptocrystalline material. The contacts between light and dark bands are weakly defined and irregular (Field of view = 0.54 mm × 0.69 mm. Photomicrograph ID# 1189A_82).