南黄海辐射沙脊群苦水洋海域晚更新世以来沉积特征及环境演化  

The core-recorded strata and environmental changes since the Late Pleistocene in Kushuiyang area of the radial tidal sandy ridge system,Jiangsu offshore,southern Yellow Sea

作　　者：季云 殷勇[1] 李清 王爱华[2] 

机构地区：[1]海岸与海岛开发教育部重点实验室,南京大学地理与海洋科学学院海洋科学系,南京210023 [2]地质矿产部南京地质矿产研究所,南京210016

出　　处：《南京大学学报（自然科学版）》2015年第3期641-657,共17页Journal of Nanjing University（Natural Science）

基　　金：国家重大科学研究计划项目(2013CB956500);国家自然科学基金(40776023)

摘　　要：本文通过钻孔沉积相分析和钻孔对比,辅以粒度、Sr/Ba环境指标和矿物分析,从下到上划分出5套沉积层序,即SU1(中低潮滩→高潮滩)、SU2(中低潮滩→高潮滩)、SU3(洪泛平原)、SU4(滨岸沼泽和潮滩)和SU5(潮流沙脊-潮流通道).钻孔对比显示,由于海侵过程中的潮流侵蚀作用,苦水洋海域的地层分布非常不均一,尤其是海侵早期地层均被侵蚀得支离破碎.结合年代地层数据,重建了苦水洋海域晚更新世以来的环境演化,除末次冰期极盛期陆地暴露以外,研究区均受潮流控制,氧同位素3阶段发育潮滩沉积,全新世高海面以来发育潮流沙脊.沙脊的频繁迁移可能是造成沙脊年龄偏轻的主要原因.晚更新世以来的海平面波动以及海侵过程中的潮流侵蚀控制了研究区的环境变化和地层结构.Based on the analysis of sedimentary facies and corns correlation augmented by the characteristics of grain size,Sr/Ba ratio as an environmental indicator and mineral analysis,the corn strata,from the bottom to top were divided into five sedimentary sequences：SU1（low-mid intertidal flat→high intertidal flat）,SU2（low-mid intertidal flat→high intertidal flat）,SU3（river-floodplain）,SU4（littoral marsh and tidal flat）and SU5（sand ridge-tidal channel complex）.The correlation demonstrates that due to the tidal erosion during the process of transgression,stratigraphic distribution is very uneven in Kushuiyang area,especially for the early Holocene deposits which were eroded thoroughly with little left.Combined with data of AMS ^14 C and OSL,the process of environmental changes was reconstructed in the Kushuiyang area since Late Pleistocene.In addition to the land exposure in the last glacial maximum,the study area has been controlled by the tides.In MIS3,It developed into tidal flat and later tidal sand ridge during high stand of the Holocene.The main reason for young ages of sand ridges was the frequent migration,so that the deposits have been renewed in an order of 102 a.In the research area,the environmental changes and stratum structure are mainly controlled by the sea-level changes and tidal erosion during transgression since the Late Pleistocene.

关 键 词：沉积相 钻孔对比 地层结构 沉积环境演化 苦水洋海域 

分 类 号：P736[天文地球—海洋地质]