Figure F7. Digital photomicrograph (crossed nicols) of a sandy silty claystone containing subrounded basalt and acidic volcanic rock fragments, unaltered detrital sand-size grains of angular plagioclase, hornblende, and planktonic foraminifers tests. Note the multiple twinned and zoned plagioclase grains (interval 180-1115C-12R-4, 144-148 cm).