摘要:Diversion of the Yellow River is a unique geological event in offshore China,causing changes of the sedimentary environment in eastern China Seas.The last diversion took place in AD 1855,with the estuary diverted from the Yellow Sea into the Bohai Sea.The identification of the river diversion events in the shelf sediments would not only provide the definite ages for the sediments,but also give a clue for better understanding of the sedimentation in that area.In this study,210 Pb,grain size,geochemical element,and foraminiferal data in core H205 from the north Yellow Sea were systematically investigated.A high-resolution sedimentary record was established,which was coupled with the Yellow River diversion and runoff changes.The results show that the foraminiferal composition and foraminiferal abundance of the sediments from the north Yellow Sea had good response to the Yellow River diversion in 1855.Before the change,shallow water assemblages dominated the foraminifera,and the abundance of each foraminiferal species was very low.After the diversion event,the abundance of most foraminifera increased sharply,with a maximum increase of 16 times,and the assemblage was still dominated by shallow water species.Furthermore,the changes in foraminiferal abundance in the core sediments corresponded well with the discharge fluctuation of the Yellow River since 1855.When the Yellow River began entering the Bohai Sea,the Yellow River water,which is rich in nutrients,along with the coastal currents affected the north Yellow Sea,increased the primary productivity in the north Yellow Sea,which is the main reason for the abrupt increase and fluctuation of foraminiferal abundance in this area.At the meantime,the East Asian winter monsoon could also promote the development of nearshore foraminiferal species by enhancing the coastal currents.
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佛山陶瓷 佛学研究 北大佛学 中国佛学 佛教文化 佛教文化研究 藏外佛教文献 汉语佛学评论 佛山科学技术学院学报·自然科学版 佛山科学技术学院学报·社会科学版 Journal of Ocean University of China Chinese Journal of Oceanology and Limnology相关文章
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