Figure F14. Digital photomicrograph (plane-polarized light) of a moderately sorted, fine-grained volcaniclastic sandstone with a silty clay matrix. This comprises common rounded plagioclase phyric basalt clasts and detrital grains of amphibole, biotite, quartz, and feldspar. Common planktonic foraminifers (Sample 180-1118A-35R-1, 140-143 cm).