| 摘要: |
| 对南黄海辐射沙洲中心沿岸地区两个钻孔采用高密度、定量采样方法进行了有孔虫和沉积学分析。结果表明，该地区晚更新世晚期可能发育了古长江河道、河口、河流边滩或河漫滩以及泛滥平原乃至泛滥湖沼等陆相沉积环境。进入全新世，则先后依次出现了潮滩、河口、潮滩、潮流沙体和潮滩，及至最终成陆。 |
| 关键词: 辐射沙洲 钻孔分析 有孔虫 古环境 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目，49236120号;南京大学海岸与海岛开发国家试点实验室成果：SCIEL21199104号 |
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| CHANGES IN DEPOSITIONAL ENVIRONMENTS IN THE AREA NEAR THE CENTER OF THE NORTH JIANGSU RADIAL BANKS SINCE THE LATE PLEISTOCENE |
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ZHU Xiao-dong, REN Mei-e, ZHU Da-kui
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State pilot Lab of Coast and Island Exploitation, Nanjing University, Nanjing, 210093
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| Abstract: |
| The North Jiangsu Radial Banks (NJRB) on the inner shelf of the southwestern Yellow Sea is one of the largest sand bank systems in the world. Its origin has been debated for over a decade. The major disagreement lies in that whether or not the ancient Changjiang River once ran through the radial central area of the NJRB. Based on foraminiferal and sedimentological analysis of two coastal cores collected from the radial central area of the NJRB, the following scenario of the ancient environment is suggested. During the late Pleistocene, the sedimentary environment was non-marine. Foraminifera appeared only in the bottom section, indicating an estuarine (the ancient Yangtze River) environment. Then there was a fluvial sedimentary environment, distant from the river mouth, namely beyond the tidal limit. Within the deposits no marine fossils were found. The subenvironment may have included river channels, bank flats, flood plains and lakes. The hard dark green mud may have resulted from a flood plain or lacustrine environment. The Holocene sediment record represents sea-related environments. The environment evolved from a tidal flat at the beginning of the Holocene to estuarine bay and near-shore environments, similar to the present tidal sandbank environment. Finally, the area changed into tidal flats and eventually became land. The results suggest that the NJRB may have a sediment source from the late Pleistocene Changjiang River delta. |
| Key words: Radial sand banks, Core analysis, Foraminifera, Paleo-environment |
