Figure F12. Photomicrographs in plane-polarized light reveal characteristic lithologic components of Units I, II, and III. A. Sample 191-1179B-4H-1, 100 cm, clearly shows rounded to subrounded tests of diatoms in the diatom ooze of Unit I. B. Sample 191-1179B-5H-3, 106 cm, documents diatom-rich clay, which is the predominant lithology in Unit I. C. Sample 191-1179C-20H-4, 40 cm, shows tests and spines of radiolarian ooze in Unit II. D. Sample 191-1179C-24H-4, 98 cm, documents ferruginous zeolitic clay in Unit III.