江苏中部海岸西洋潮流通道区域晚更新世古地貌与沉积体系研究  

Paleo-geomorphology and sedimentary systems of the Xiyang tidal channel on the central Jiangsu coast at the late Pleistocene

作　　者：王辉[1] 夏非 张永战[1] 高抒 李家彪 Wang Hui;Xia Fei;Zhang Yongzhan;Gao Shu;Li Jiabiao(Key Laboratory of Coast&Island Development of Ministry of Education,Nanjing University,Nanjing 210023,China;School of Urban and Resource Environment,Jiangsu Second Normal University,Nanjing 210013,China;State Key Laboratory for Estuarine and Coastal Research,East China Normal University,Shanghai 200062,China;Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China)

机构地区：[1]南京大学海岸与海岛开发教育部重点实验室,江苏南京210023 [2]江苏第二师范学院城市与资源环境学院,江苏南京210013 [3]华东师范大学河口海岸学国家重点实验室,上海200062 [4]自然资源部第二海洋研究所,浙江杭州310012

出　　处：《海洋学报》2019年第3期134-142,共9页

基　　金：国家重大科学研究计划项目(2013CB956500);江苏省自然科学基金面上项目(BK20171341);江苏省高等学校自然科学研究面上项目(18KJB170003);江苏第二师范学院引进高层次人才科研启动经费项目(919801)

摘　　要：南黄海曾是长江和黄河两大河流输送的陆源沉积物重要的汇,其沉积记录含有河流演化的丰富信息。江苏海岸中部、南黄海西侧、辐射沙脊群西北的西洋潮流通道及其邻区受到古黄河与古长江的交互影响,其古地貌与沉积地层等研究尚显不足。利用该区多次采集获得的长约380 km的浅层地震剖面数据,结合钻孔资料,分析了西洋浅部地震层序,探讨了其沉积环境特征。研究结果表明,西洋潮流通道区域在平均海面以下33～49 m处,存在一个强振幅、中频率、高连续性的区域性反射界面,与对比钻孔中滨岸沼泽沉积的顶面相对应,代表一个不整合的古地貌面;该界面深度的空间插值结果反演的古地貌面与下伏的沟槽状切割-充填反射结构,揭示了数条沿NE方向延伸的古水道,并集中分布于古地貌面北部相对低洼的区域,为南黄海内陆架晚更新世某古水系的一部分;该古地貌面系末次冰消期的海侵冲刷面,其上覆是全新世滨浅海沉积,下伏是晚更新世末期的洪泛平原或滨岸沼泽或充填下切古河道或古潮道等沉积。对该区域性反射界面的深入研究有助于弄清南黄海西部晚更新世以来的沉积体系演化历史,提升对辐射沙脊群形成演化的认识。The South Yellow Sea has been one of the important sinks for the terrigenous sediments transported by the Changjiang and Yellow rivers.It contains abundant information for the river migration and evolution in the sedimentary records.The Xiyang tidal channel,as one of the important tidal channels in the northwestern radial sand ridge field,is located on the central Jiangsu coast of the South Yellow Sea.It has the strong impacts from both the ancient Yellow River and Changjiang River in this area.So far,the studies on the paleo-geomorphology and sedimentary strata are still not sufficient.Based on the about 380 km long shallow seismic profiles obtained in the study area,combined with the published data of sedimentary core,the shallow seismic sequence has been studied,and concerned characteristics of the sedimentary environments have been discussed.The results indicate that there is a regional unconformable seismic reflection interface underneath the seafloor,33-49 m below the mean sea-level,characterized by strong amplitude,medium frequency and good continuity.This strong reflection interface could correspond to the top surface of coastal lacustrine deposits in the core.It is the representative for a paleo-geomorphological surface.The spatial distribution of this strong reflection interface,joint with the groove seismic structures underneath it,figure out that several ancient channels extending to the sea northeastwards and converging in the lower-lying area located in the north of the study area.The strong reflection interface is an eroded surface formed during the last deglaciation transgression.Its overlying is the shallow water deposits formed during the Holocene,on the other hand,its underlying is the deposits in flood plain or coastal marsh or ancient river or tidal channels formed during the last stage of the late Pleistocene.The further study of this regional interface is helpful to understand the evolution of the sedimentary systems in the western South Yellow Sea since the late Pleistocene,and to improve

关 键 词：地震地层 古地貌 古水系 晚更新世 辐射沙脊群 南黄海 

分 类 号：P736.222[天文地球—海洋地质]