舟山群岛朱家尖岛以东近岸海域沉积物粒度特征

Surficial Sediment Characteristics of the Inshore Area of East Zhujiajian Island,Zhoushan Archipelago

海底沉积物粒度对底栖生物、底床抗侵蚀能力以及海底工程等具有重要意义。本文通过对朱家尖岛以东海域58个表层沉积物样及4个柱状样的取样和分析，研究该海域海底沉积物的粒度特征。结果表明：该海域表层沉积物成分中，粉砂最多，平均占65．5％，黏土次之，平均占25．8％，砂极少，平均只占8．7％；平均粒径4．6～7．6φ，分选系数1．5～2．3。粒度分布上，由陆向海粒径变细，自北向南在研究区域范围内粒径变化不明显。海底沉积物在0．8m深度内垂向粒径变化很小，说明该海域沉积环境总体稳定。

The particle size characteristics of surficial seabed sediment are important to benthic organisms, controlling the resistance of the bed to erosion, and submarine engineering. We analyzed the particle sizes of 58 surface sediment samples and 4 core samples from the seabed of the inshore area of East Zhujiajian Island. Silt composed 65.5% of the sediment, clay contributed an average of 25.8%, and sand accounted for an average of 8.7%. The average particle size ranged from 4.6 to 7.6 φ, and the sorting coefficient ranged from 1.5 to 2.3. The particle size distributions show a general seaward-fining trend, but exhibit no significant change from north to south. The size distributions show little change down to 0.8 m below the seabed, indicating that sedimentation in the area has been steady and consistent.