Tidal-flat sequence controlled by Holocene sea-level rise in Gomso Bay, west coast of Korea

Intertidal deposits of Gomso Bay, western coast of Korea (eastern Yellow Sea) consist of a basement, pre-Holocene oxidized unit, and a Holocene tidal unit in ascending order. The pre-Holocene oxidized unit, a yellowish stiff mud belonging to the last stadial (or glacial) stage before 12 000 yr B.P., contains plant roots, plant fragments, and vertical and horizontal microfractures indicating soil-formation. However, it contains no marine shells or microfossils. The Holocene tidal unit is composed of lower mud facies (upper-flat mud) and upper sand/muddy sand facies (middle-to lower-flat sand), and generally shows a coarsening-upward, retrograding trend, thus reflecting a Holocene relative sea-level rise. C-14 age/depth plot for dated samples (peats and shells) shows that the relative sea-level of 7000 yr B.P. stood at about - 6.5 m from the present mean sea level, and the relative sea-levels of 4000 yr B.P. and 2000 yr B.P. stood at - 3 m and - 25 m, respectively. (C) 2001 Academic Press.