| 摘要: |
| 通过对南港工业区毗邻海域采集的40个表层沉积物样品做粒度分析，结果表明：研究区大部分采样点沉积物为粘土质粉砂，仅有少数3个采样点为粉砂，1个采样点为砂质粉砂.又根据沉积物粒度参数特征，将研究区划分为3组沉积环境：I组沉积物平均粒径相对较大，沉积物砂含量较高，水动力为中低能，根据沉积物粒径和海域位置又分为受河流影响较强沿岸流影响较弱的沉积环境(I-1组)和受河流影响较小潮流影响较大的沉积环境(I-2组)；II组为受较强河流水动力和潮流水动力双重影响的潮下带沉积环境；III组沉积物整体上颗粒较粗，水动力环境较为稳定，为受季节性湾内环流影响的沉积环境.另外，研究区西南岸潮间带向东北部，沉积物粒径变细，原因是西南岸河流将粗颗粒物质携带至潮间带，在河流和沿岸流共同作用下向北运行，受到南港工业区阻挡，粗粒沉积物沉积，细颗粒物质随水流反弹向南回流后，又在向北移动的环流作用下向东北方向移动，造成该海域沉积物偏细. |
| 关键词: 海洋地质学 粒度特征 表层沉积物 沉积环境 南港工业区 |
| DOI：10.3969/J.ISSN.2095-4972.2018.04.002 |
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| 基金项目:国家自然科学基金资助项目（41476074）；国土资源部中国地质调查局资助项目(121201006000182401) |
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| Grain size characteristics of surface sediments and the response to sedimentary environment in the coastal waters of Tianjin Nangang Industrial Zone in Bohai Bay |
| PAN Long,FANG Jing,TIAN Li-zhu,LI Yang,WANG Fu,QI Wu-yun,WANG Zhong-liang |
| (College of Geography and Environmental Science, Tianjin Normal University, Tianjin 300387, China;Tianjin Centre, China Geological Survey, Tianjin 300170, China;Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710,China;Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, Tianjin 300387, China) |
| Abstract: |
| The grain size analysis of 40 surface sediments collected in the adjacent sea area of Tianjin Nangang Industrial Zone was analyzed. The results show that most of the sampling sites in the study area are clayey silt. Only three sampling sites are silt and one sampling site is sandy silt. According to the features of sediment grain size parameters, the study area can be divided into 3 groups that belong to 3 different depositional environments. In group I, the sediment average grain size is relatively large with high content of sand in the sediments where the hydrodynamic force is low and medium. Further, the sediment grain size and the location of sea area can be divided into two depositional environments according to the relative weak influences of river. That is the sedimentary environment under the influence of multiple dynamics (I-1) and the sedimentary environment (I-2) affected strongly by the smaller tides and weakly affected by the river. In group II , the sedimentary environment in the subtidal zone is influenced by the hydrodynamic forces of the strong river and the tidal current hydrodynamics. In Group III, The sediments grain sizes are coarse sands and the hydrodynamic environment is relatively stable, which affects the sedimentary environment of the seasonal bay circulation. In addition, the intertidal zone in the southwest bank of the study area turned to the northeast, with the sediment grain size becoming smaller. The reason is that the coarsegrained matter was carried to the intertidal zone by the river in the southwest bank, Under the joint action of rivers and coastal currents, they run northwards and are blocked by Nangang Industrial Zone. Deposits of coarse sediments, fine-grained particles flow back to the south with the rebound of the water flow and then move to the northeast direction under the current of northward movement, resulting in the sediment particles of the sea area thinning. |
| Key words: marine geology grain size characteristics surface sediment deposition environment Nangang Industrial Zone |
