Figure F49. Features of indurated volcaniclastic silty claystone (Unit 12) at the basal contact of the lower palagonitized crystal vitric tuff (Sample 200-1223A-6X-3, 100-117 cm). A. Scanned image of the contact. B. Close up of white vugs just beneath the tuff. C. Detail of the vein network linking the vugs near the base of the lower piece. D. Photomicrograph of anhydrite in a vug (crossed polars). E. Embossed image, lighted from the top, showing grains of minerals in a vug. Note grains with pseudohexagonal cross sections. F. Bladelike mineral in rosettes in a space along a vein (crossed polars). G. Recrystallized matrix of the claystone (plane-polarized light). H. Zeolite filling a circular center of a former radiolarian test. I. Tiny rosette of a secondary mineral (cristobalite?) in the recrystallized matrix of the claystone.

Figure F49. Features of indurated volcaniclastic silty claystone (Unit 12) at the basal contact of the lower palagonitized crystal vitric tuff (Sample 200-1223A-6X-3, 100-117 cm). A. Scanned image of the contact. B. Close up of white vugs just beneath the tuff. C. Detail of the vein network linking the vugs near the base of the lower piece. D. Photomicrograph of anhydrite in a vug (crossed polars). E. Embossed image, lighted from the top, showing grains of minerals in a vug. Note grains with pseudohexagonal cross sections. F. Bladelike mineral in rosettes in a space along a vein (crossed polars). G. Recrystallized matrix of the claystone (plane-polarized light). H. Zeolite filling a circular center of a former radiolarian test. I. Tiny rosette of a secondary mineral (cristobalite?) in the recrystallized matrix of the claystone.