FIGURE 20.-SEM photographs showing silt and day fraction of the volcanic ash type (A),
organic ooze (B-D), and sapropel (E and F): A, sample LY 11-3, h; B-D, LY 11-3, e; E-F, LY II-3,
i (/ = feldspathic grain, p = pyrite framboid). (Volcanic glass shards in A; explanation in text.)