Figure F111. Photomicrograph of a quartz-pyrite vein. The quartz grains contain dark trails subparallel to the vein margins. These trails are defined by fine fluid and solid inclusions and strongly suggest that this vein was formed by crack-seal mechanism (Sample 193-1188F-15Z-1 [Piece 8, 55-58 cm] in cross-polarized transmitted light; width of view = 5.5 mm. Photomicrograph ID# 1188F

Figure F111. Photomicrograph of a quartz-pyrite vein. The quartz grains contain dark trails subparallel to the vein margins. These trails are defined by fine fluid and solid inclusions and strongly suggest that this vein was formed by crack-seal mechanism (Sample 193-1188F-15Z-1 [Piece 8, 55-58 cm] in cross-polarized transmitted light; width of view = 5.5 mm. Photomicrograph ID# 1188F_82; thin section 81).