At location 4, the terrace deposits are overlain by loess deposits
that include tephras WP, OrP, Toya, and To-CP (Figs. 7 and 8). Loess
deposits between terrace deposits and WP are about 150 cm thick,
clearly different from the 50 cm thickness reported by Kuwabara
(2004). This evidence shows that the termination of marine sediment
deposition was much older than the eruption of tephra WP.
The loess deposits between WP and OrP are 70 cm thick, and those
between OrP and Toya are 200 cm thick (Fig. 7). Tephra ZP is absent
here, probably because of weathering.