| In order to probe material constitutes of sediments, material source and formation history in the Bohai Sea mud area (BSMA) during the Holocene and their environmental implication, grain size, mineral and chemical compositions of cores in various parts are analyzed combined with shallow seismic profiles, AMS 14C dating, micropaleontologic assemblage, stable isotopes and paleomagnetic data. Results show that the Yellow River has even flowed from the southern part of the Bohai Sea during the early Holocene, and that sediments discharged from the Yellow River affected the sedimentation in the Bohai Sea, but sedimentary environment and influence by the Yellow River matter at various cores are different.Major segment of the BSMA starts to form at about 6000 a BP, when sedimentary records break, denoting with transformation of the redox environment, changes of seawater temperature and salinity, accelerating sedimentation rate and appearance of planktonic foraminifera, which can be illuminated with the impact of the Yellow Sea Warm Current (its extension). In the last 4500 a BP, heavy mineral assemblage and chemical compositions in core sediments of the studying area closed to the corresponding ones in the Yellow River sediments, indicating that the effect of the Yellow River sediments on the sedimentation becomes dominant. Although closing to the Yellow River mouth, the studying area has no faster sedimentation rate than other areas, reflecting that the Yellow River sediments to the Bohai Sea mud area are far less than those to the Yellow Sea due to transporting mechanism. Two geomagnetism pole drifts during the Holocene are recorded in northern part of the BSMA, occurring at 2800~3100 aBP (corresponding to Starno event) and 7500~8200 aBP respectively. Because climate, material source and sea level change obviously compared with before and after the drift, we speculate that geomagnetic pole drift has significant impact on climate.
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