Holocene Sea-Level Fluctuations in the Garolim Bay Tidal Flats, West Coast of Korea

Abstract

Twenty-seven facies are identified from stratigraphy of twelve vibracores in the Garolim tidal flats of west coast of Korea based on sediment characteristics and microfossil analysis. As a result, seven paleoenvironments are interpreted from these facies. The seven paleoenvironments are 1) supratidal flat, 2) upper intertidal flat, 3) upper middle intertidal flat, 4) middle middle intertidal flat, 5) lower middle intertidal flat, 6) low intertidal flat and 7) subtidal flat. The Holocene sea-level curve is constructed by forty-one 14C (AMS) dates of foraminifera specimens, shells, peats, woods and organic materials of vibracore sediments. Six fluctuations of sea level are recognized. The sea-level in Garom Bay was positioned 10.9 m below the present MSL (mean sea level) in 8,150 yrs BP and rapidly rised with a rate of 2.3 cm/yr until 7,750 yrs BP reached 1.7 m below the present MSL (mean sea level). Short drop of 3 m in sea level occurred within 200 yrs from 7,750 yrs BP to 7,550 yrs BP. Since 7,550 yrs BP, two rises and drops are identified. Two rises of sea level occurred about 4,000 yrs BP and about 2,000 yrs BP with 2 m above the present MSL.