山东半岛中南部滨浅海地区表层沉积物分布特征及形成机制

对取自山东半岛中南部滨浅海地区的137个表层样品进行了沉积物粒度分析,并在此基础上划分了沉积物类型,探讨了沉积物粒度分布特征和沉积物类型与物质来源和沉积动力条件的关系。研究表明,表层沉积物中粉砂组分平均含量最高,超过60%,含量等值线与海岸平行呈东北-西南向分布,近岸及河口地区含量最高,向海方向逐渐减小;粉砂和砂质粉砂是分布最广泛的沉积物类型,约占研究区面积的60%以上。崂山头以东海域沉积物分布类型简单、分布面积大,而崂山头以西海域包括胶州湾海域,沉积物类型复杂多样,且呈斑块式分布;崂山头以西主要来源于山东半岛南部的中小河流和海岸侵蚀所带来的半岛型物质,受到潮流和波浪等动力的影响而形成;崂山头以东地区主要是来源于黄河细颗粒物质,物质输运及分布受到黄海暖流、黄海沿岸流和近岸流系的控制。

DISTRIBUTION PATTERN AND DEPOSITIONAL MECHANISM OF SURFACE SEDIMENTS OFFSHORE SOUTHERN SHANDONG PENINSULA

Grain-size analysis and sediment classification for 137 surface sediment samples taken from the offshore area of the Southern Shandong Peninsula have been carried out to reveal the distribution pattern of surface sediments and its relation with source and sedimentary environment.The results indicate that silt component dominates the surface sediment and decreases gradually seaward with the isopleths of content parallel to the coastline in northeast-southwest direction.Silt and sandy silt are the deposits distributed most widely in this area and cover almost 60% of the total research area.There are two different distribution patterns around the cape of Laoshantou.In the east to the Laoshantou,the surface sediments are simple and widely distributed.The sediment mainly comes from the Yellow River carried by the Yellow Sea Coastal Current,Yellow Sea Warm Current and near shore current system.In the west of the Laoshantou, however,the surface sediments are rather complex and diversified and distributed as patches.The sediment in this area is originated from the Shandong Peninsula and reworked by the tidal current and wave.