showed the sediment distribution of the gulf, but they considered
that the amount of calcium carbonate was too low to affect the
grain size parameters in the gulf of Thailand and thus analyzed
the whole sample with calcium carbonate. However, the UGOT is abundant in shell fragments, which are calcium carbonate-rich and
are significant in determining the grain size composition of sedi-
ments (Fig. 3B). The total sediment color in the study of Emery
and Niino also show that samples near the Chao Phraya River
mouth is yellow brown, whereas the adjacent bank is olive brown.
The averaged Mz of sediments collected from the Chao Phraya
River and Bang Pakong River is 55 lm (Fig. 3B).