Sedimentary Environment and Its Evolution of Qiongzhou Strait and Nearby Seas since Last Ten Thousand Years
Chen Liang
Zhang Yufen
Li Tuanjie
Yang Wenfeng
Chen Jing
Abstract：About 600 surface sediment samples were collected in the Qiongzhou Strait and the surrounding marine environment, and were analyzed particle-size distribution.Results show that the sediments are dominated by sand and gravel sandsinside the Qiongzhou Strait,and the sediments change gradually from coarser to finer particles,mostly silt and clay sized,away from the inner strait areas to the outside areas.The boundaries of sand sediments spread arched in the east mouth,whereas they spread in the shape of fingers in the west.The distribution of grain size frequency curve can be divided into 5 categories,(a)single kurtosis to the east strait,(b)east strait double kurtosis,(c)single and double kurtosis in the strait,(d)west strait single kurtosis,and (e)west strait double kurtosis.The sediment transport trends was analyzed by the GSTA model,which shows that the sediment mainly moved from the north and south sides to the middle into the strait,whereas in the east area the sedi-ments moved obviously from the strait to the outside sea,and there was a northward trend in the west area.Both the distribu-tion of grain size and the transport trend of the sediments show that the sediments mainly originated from the bottom and side of the strait which were eroded by the tides.Based on interpretation of the modern depositional environment in the Qiongzhou Strait,combined with the grain size characters and the AMS-1 4 C data of 4 core samples which were obtained by the gravity cor-er,it is concluded that the final formation of the Qiongzhou Strait began about 8 000 a ago due to the rise of sea level,and the initial landform was shaped by the tides.In addition,about 5 000 to 4 600 a ago,the Qiongzhou Strait has been in a stage of rapid development,and the tidal deltas spread most widely until the end of the warm period when the sea level dropped and the tide power weakened,which led to the stabilization and formation of the present Qiongzhou Strait.
Keywords：grain sizesedimentsedimentary evolutionQiongzhou Straitoceanography
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 696-704 )