大连复州湾底质沉积物粒度特征与沉积环境分析

对辽东半岛西部复州湾海域底质沉积物样品进行粒度分析结果表明,其粒度特征有较大差异:样品平均粒径值为1.2~6.5Φ;分选系数为1.4~2.6,分选为较差—差;偏度特征表现为极正偏和极负偏并存。粒度的空间分布存在一定分异规律,由湾内至湾外粒径表现出粗—细—粗的变化特征。粒度变化是对该区域物质输运和地形变化的响应,借助Weibull分布,推断河流携带物质可以被推送至5 m等深线外堆积,5~10 m等深线间沉积物表现为细粒的浅海台地沉积,10 m等深线以外沉积物受河流的影响微弱。矿物学证据也表明,河流输运对湾内沉积物贡献有限,仅限于5 m 等深线以内的水下三角洲,湾内沉积物主要来自于辽东湾沿岸冲刷和湾内基岩的剥蚀。

Grain size characteristics of surface sediments and the response to sedimentary environment in Fuzhou Bay,Dalian

Marine surface sediments from the Fuzhou Bay, the western Liaodong Peninsula, were obtained for sedimentary analysis. The characteristics of grain size are corresponding to the sedimentary environment. The grain size parameters show a significant difference among samples from various positions, as the average grain sizes range from 1.2Φ to 6.5Φ. The grain sizes are all poor sorted (1.4~2.6) with fine to coarse skewness, and display a spatial change as fine to coarse to fine from the estuary to the shallow sea. The 5 m and 10 m isobaths mark the edge of these boundaries, probably resulting from sediment transport and submarine topography. Most of river sediments can be transported to the 5 m isobath, and sediments in the area between 5 m to 10 m isobaths are mainly from river and outer sea, while little river sediments can get to west of 10 m isobaths. With the evidence of both Weibull function and mineralogy, most of the sediments in Fuzhou Bay are from the erosion of Liaodong Bay and Fuzhou Bay.