Figure F22. Photomicrographs of complex veins showing an early phase of botryoidal to bladed carbonate followed by a second phase of fibrous radiating fans of carbonate (Sample 198-1213B-31R-3, 73-75 cm). The vein fills much of the field of view. Out of the field of view, the second phase is associated with minor quartz. Darker (more isotropic) areas on either side of the carbonate cement are clay-rich alteration zones. On the right, the alteration zone is crossed by later fractures filled by carbonate. Unaltered host rock can be seen on the extreme left. The upper view is in plane-polarized light, and the lower view is with nicols crossed.

Figure F22. Photomicrographs of complex veins showing an early phase of botryoidal to bladed carbonate followed by a second phase of fibrous radiating fans of carbonate (Sample 198-1213B-31R-3, 73-75 cm). The vein fills much of the field of view. Out of the field of view, the second phase is associated with minor quartz. Darker (more isotropic) areas on either side of the carbonate cement are clay-rich alteration zones. On the right, the alteration zone is crossed by later fractures filled by carbonate. Unaltered host rock can be seen on the extreme left. The upper view is in plane-polarized light, and the lower view is with nicols crossed.