Holocene sedimentation rates and their response to fluvial supply on the west coast of Bohai Bay

Taking cores from three drill holes along the western coast of Bohai Bay as the study basis and collecting materials through cutting through the upper marine bed deposited during Holocene as samples, the authors dated shells and charcoals by AMS 14C and calculated the average sedimentation rate. The spatial-temporal relationship between the Holocene sedimentation rates of drill holes and sediments transported by rivers was discussed combined with grain size and development of adjacent ancient river delta. The results indicate that various sedimentation rates occurred in different periods in Holocene and such a variety reveals different sediment supplies along the western coast of Bohai Bay. From early Holocene to early period of mid-Holocene, the low sedimentation rate (0.03~0.07cm/a) and coarse sediments along the whole western coast presented less impotent fluvial input at that time. During 6.43~4.96ka cal BP, the rising sedimentation rate (0.59~0.93cm/a) and upward-coarse grain size succession implied that Chaobai River, Yongding River and Luanhe River dumped sediments in the northern part of the west coast of Bohai Bay. In 3.68~2.67ka cal BP, the Yellow River downloaded its sediments in the southern part of the area indicated by the high sedimentation rate (0.27~1.4cm/a) and upward-coarse grain size succession, while Haihe River emptied its sediments to the middle part of the area in 2.29~0.24ka cal BP with sedimentation rate being 0.55~0.91cm/a.