Figure F17. Close-up photograph of interval 183-1141A-21R-3, 120-140 cm, shows the change from basement Unit 5 to Unit 6. Note that the smooth undulating vesicular base of Unit 5 is highly altered, which probably obscures the small vesicles characteristic of chill zones. The top of Unit 6 seen in the photo shows some of the best preserved parts of the upper breccia. Note the subrounded clasts with subangular vesicles and the clay-filled voids.