Comparative Study of Sediment Grain Size Characteristics in the Sand Ridge Area of the South Yellow Sea and the East China Sea

对南黄海和东海典型沙脊区域沉积物的特征的研究仍比较缺乏。根据2022年和2023年表层沉积物采样和测试资料，对研究区沉积物粒度特征进行分析讨论。结果表明，南黄海沙脊沉积区峰脊或浅滩区域和其间的槽洼区域沉积物相比有明显差别，水动力的改造比较经常而且强烈。东海沙脊沉积区沙脊沉积物和沙脊间的槽洼沉积物相近。南黄海沙脊为活动性沙脊，沉积物为多源、多期沉积，且不稳定。东海沙脊沉积形成后，后期的改造和现今的活动性都比较弱。东海沙脊沉积主要是低海面或海侵早期的河口三角洲或滨浅海相沉积。后期的改造主要是细颗粒的粉砂和粘土再悬浮和再沉积，沉积物有一定程度的粗化，但仍然总体上保持了原来的特征。Studies on the of sediments characteristics in typical sand ridge areas in the South Yellow Sea and East China Sea are still relatively lacking. Based on the sediment grain size test data in 2022 and 2023, the sediment grain size characteristics of the study area were analyzed and discussed. The results show that there is a significant difference between the sediments in the peak ridge or shallow beach regions of the South Yellow Sea sand ridge deposition area and those in the trough regions between them, and the hydrodynamic modification is more frequent and intense. In the East China Sea, the sediments of the sand ridges and the sediments of the troughs between the ridges are similar. The sand ridges in the South Yellow Sea are active sand ridges, and the sediments are multi-source, multi-phase deposits and unstable. After the formation of the East China Sea sand ridge deposits, the later modification and present-day activity are relatively weak. The East China Sea sand ridge deposits are mainly estuary or coastal phase deposits in the early stage of low sea surface or transgression. The later modification is mainly fine-grained silt and clay resuspension and redeposition, and the sediments are coarsened to a certain extent, but still generally maintain the original characteristics.