苏北近海平原沉积物的粒度特征及其环境意义

Grain Size Characteristics and Their Environmental Significance of Northern Jiangsu Coastal Plain

对射阳海滩、兴化浅孔沉积物的粒度特征进行对比分析,研究结果表明：典型的海相沉积物频率曲线为单峰正态分布,主峰范围窄,集中在50~65μm,砂含量高达40%,粘土含量不到10%,概率累积曲线存在推移组分且占到5%左右,属海滩沉积;典型的陆相沉积物频率曲线为单峰偏负态分布,主峰范围较广,位于5~30μm之间,砂含量最大值仅11%,概率累积曲线中无推移组分,跃移占70%左右,属于静水沉积;最后,对比讨论建湖海陆过渡相不同层段沉积物的粒度特征分析其沉积环境：434-395 cm层段属于湖沼相沉积;395-295 cm层段初步判断为泻湖沉积环境;295-150 cm层段可能受到海水影响;150-110 cm层段初步判断属于湖泊沉积环境.

By horizontal comparison for grain size characteristics of Sheyang beach,Xinghua shallow drilled sediment,the results showed that the frequency curve for typical marine sediment is single-peak normal distribution,which main peak is narrow and concentrated in the 50～65μm,the content of sand up to 40%,clay less than 10%,and the process content in the cumulative probability curve accounted for 5%,which belonged to beach deposits;Moreover,the frequency curve for typical continental sediment is single peak partial negative stale distribution and broader peak between 5～30μm,the maximum content of sand only 11%,the process content in the cumulative probability curve has none,saltation accounted for 70%,which attribute to lake sediment;Finally,discussion the grain size characteristics for transition phase of sea and continental sediment in Jianhu found that 434～394cm layers belongs to lake and marish sediment;395～295cm layers is preliminary judge for the lagoon sedimentary environments;295~110cm layers affected by sea water;150～110cm layers are lake sedimentary environment.