摘要
2006年6月在胶州湾采集柱状岩芯并对沉积物进行粒度分析,结果表明,胶州湾沉积物存在显著的空间和时间分异。从平面分布上看,由南往北表层沉积物颗粒逐渐变粗,分选变差;粉砂含量逐渐减少,砂含量逐渐增加。粒径趋势分析亦显示了胶州湾内沉积物输运的空间分异特征:内湾西北部浅水区的沉积物存在向南偏东方向的净输运,外湾浅水区沉积物则向黄岛前湾内运移,与10a前的沉积物运移趋势基本一致;青岛近岸海域沉积物沿沧口水道向湾顶输运。从垂向上看,柱状岩芯的沉积层具有互层层理和多个粒级的环境敏感组分,并且早期(底部)的沉积物颗粒偏粗。根据本文柱状岩芯的210Pb测年结果并与10a或数十年前的分析数据相比,胶州湾的平均沉积速率有所降低。胶州湾柱状岩芯呈现出的平面与垂向上的时空分异特征不但与局地的水动力变化、沉积物输运有关,还与物源供应、沉积环境的演化和人类活动的影响有关。
Sediment cores were collected in the Jiaozhou Bay in June 2006. The grain size analyses on the sub-sample taken from the cores were undertaken. The results show that the sediment of the Jiaozhou Bay has the various distribution patterns in many aspects in different spatio-temporal scales. Horizontally, grain size of surfacial sediment （0-4 cm） from the cores becomes coarser and worse sorted northward in the Bay, also the sand component increases but silt decreases. In addition, the grain size trend analysis shows that there is a net sediment transport towards the SSE in the shallow sea area （water depth〈10 m ） of the northwest of the Inner-Jiaozhou Bay. The sediment at the Outer-Jiaozhou Bay within the shallow sea （2 m 〈 water depth 〈5 m ） moves to the Front-Huangdao Bay. The above sediment transport patterns are similar to those obtained ten years ago. Since the near-shore area at Cangkou is close to the Qingdao city, which suffers human activity impacts that change the sediment transport pathway towards the top of the Jiaozhou Bay along the Cangkou Channel. The vertical sediemnt structure of the cores could represent the temporal sedimentary environment evolution. For example, the cores have alternative beddings and multiple grain size classes of environment sensitivity, and the sediment near the core bottom becomes coaser. Nevertheless, the sediment water contents are between 20% and 50%, which has a significant positive relationship with mean grain size （Ф）, clay content and silt content, but negative correlation with sand content. In comparison with the deposition rate 10 years ago, the recent deposition rate in a centurial scale becomes decreasing which may result from the sediment supply from the uper fiver of the watershed and the human＇s castoff from the Qingdao City. Thus, the temporal and spatial variations of sediment distribution and sediment transport are shown present in the Jiaozhou Bay, which may be related with not only the local hydrodyanmics and sediment dynamics, but also the sediment sources and environment changes and human activities
出处
《海洋通报》
CAS
CSCD
北大核心
2008年第3期57-66,共10页
Marine Science Bulletin
基金
国家908专项(908-02-03-08)
教育部留学回国人员科研启动基金
教育部“新世纪优秀人才支持计划”(NCET-06-0446)
关键词
沉积物粒度参数
粒径趋势分析
柱状岩芯
胶州湾
Sediment grain-size parameter
Grain-size trend analysis
sediment core
Jiaozhou Bay
