【摘要】 天津市地处华北平原沉积区,沉积物来源广泛,其中黄河沉积物成为全新世以来形成天津陆地的重要组成部分.特别是约5 000年前最后一次大规模海退之后,黄河北流对天津地表地貌的变化起到了决定性作用.为了探究黄河沉积物特别是历史上的黄河北流对天津地貌的影响,在天津七里海和北大港2个湿地提取了沉积物样品,分析了黄河沉积物标志层的沉积物性质,系统讨论了历史上对天津地貌和海岸线影响显著的3次黄河北流事件及其在典型湿地的沉积记录.研究表明:公元前2 000年到公元前450年,禹河曾在天津入海,影响范围是天津西郊以东、七里海以南的广大区域;公元前750年到公元11年,《汉志》河下游河道多次摆动,支流众多并影响到天津南部,北大港在此期间沉积了在时空上不连续的黄河沉积物,显示了河道摆动的结果;公元1048年到公元1128年,北宋时期黄河北流在天津泥沽入海,直至把入海口推至塘沽,推动天津海岸线东移,显著改变了天津的海岸线型,这一事件对天津滨海新区的形成产生重要影响,是滨海新区形成的地貌基础.更多还原

【Abstract】 Tianjin is located in the North China Plain which is formed by large and diferent kinds of sediments,and the sediments from the Yellow River had became the main source for the Tianjin’s landscape since the beginning of Holocene. The north flow of the Yellow River played a role in the form of Tianjin’s landscape especially after the great marine regression before 5 000 years ago. In order to explore the influence of the sediments from the Yellow River,especially the north flow of the Yellow River on Tianjin landscape,sediment cores was exacted from Qilihai wetlands and Beidagang wetlands, the sediment character of the Yellow River reference mark was analyzed, and three times of north flow of the Yellow River events which significantly impacted the landscape and coastline of Tianjin in history and its sedimentary record in typical wetland were systematically discussed. The results show that Yuhe River ran into Bo Sea from Tianjin from 2 000 BC to 450 BC,which influenced the east of Xijiao and the south of Qilihai in Tianjin. Hanzhi River which had many tributaries swag frequently from 750 BC to 11 AC,it influenced the south of Tianjin,and the Yellow River sediments which were discontinuous on space time were deposited in Beidagang, they were the results of the tributaries swag. The north flow of the Yellow River flowed into Bo Sea from Tianjin Nigu River until the estuary was pushed to Tangu from 1 048 AC to 1 128 AC,and it not only sharply pushed the coastline to the east,but also changed the profile of the coastline. The sediment from this period had a significant effect on the formation of Tianjin Binhai district, which was also the landscape basement of Binhai district.更多还原