人工岛建设对龙口湾表层沉积物粒度及黏土矿物组成特征的影响

摘要

Based on the laser particle size and X-ray diffraction (XRD)analysis,sediment samples collected from the Longkou Bay in 2013 were determined to discuss the impacts of large-scale offshore construction of artificial islands on the distributions of grain size and clay components in sediments.Results showed that,silt was predominated(59.1%),clay(18.05%)and sand(1 9.05%)components were closer.The clay components in sediments of the Longkou Bay were close with those in the Laizhou Bay,and the clay components were in the order of illite>smectite>chlorite>kaolinite,but there still exists certain differ-ences between individual mineral content.Surface sediment particle size distribution and the combination of the clay mineral characteristics showed that although local river ,wind sediment and the shore erosion is given priority to the Longkou Bay sediments,the construction of coastal large-scale artificial island also has an important influence on its combination features.Grain size of clay content on the slightly elevated,sand content declined slightly;Clay mineral composition on the show is about 24.55% increase in the maximum content of smectite,chlorite and kaolinite have the maximum content decreased about 35%,and the high-est levels of illite haven't changed much.Through the research of the surface sediment particle size distri-bution and composition of clay mineral characteristics in the Longkou Bay,can reveal large-scale artificial island construction has given a certain extent influence on the sedimentary environment of the Longkou Bay.%通过对2013年采自龙口湾的表层沉积物样品进行激光粒度分析和 X-射线衍射(XRD)分析，根据其表层沉积物粒度及黏土矿物组成分布特征，来探讨大规模人工岛建设对龙口湾表层沉积物粒度分布及黏土矿物组成特征的影响。结果表明，龙口湾沉积物粒度以粉砂为主(62.90%)，黏土(18.05%)和砂(19.05%)的质量分数相近。龙口湾表层沉积物的黏土矿物组成与莱州湾整体沉积物组成相近，其不同组分质量分数表现为伊利石>蒙皂石>绿泥石>高岭石，但个别矿物的含量仍存在一定差异。表层沉积物粒度分布及黏土矿物的组合特征表明，尽管龙口湾的沉积物仍以沿岸河流输沙、风沙和岛岸侵蚀为主，但沿岸大规模人工岛建设已对其组合特征产生重要影响。粒度组成上黏土质量分数略有升高，砂质量分数略有下降；黏土矿物组成上表现为蒙皂石的最大质量分数升高24.55%，绿泥石和高岭石的最大质量分数均下降35%左右，而伊利石质量分数最高且变化不大。通过对龙口湾表层沉积物粒度分布及黏土矿物组成特征的研究，可在一定程度上揭示大规模人工岛建设对龙口湾的沉积环境的影响。