晚全新世以来长江口北支XL1孔有孔虫组合与气候、海平面变化研究

通过对长江口北支XL1孔48个样品的有孔虫定量分析,将该孔划分为3个有孔虫组合带（含有8个组合亚带）,并将其与崇明岛北部的永隆沙CY孔沉积特征进行对比,确定了XL1孔为晚全新世以来的沉积。对比分析两孔有孔虫组合特征,参照CY孔孢粉组合分析结果,对长江口北支XL1孔揭示的气候与海平面变化进行研究。XL1孔3个有孔虫组合带所反应的气候变化特征依次为温和略湿（后期又转暖一些）→温而略干→温暖湿润;海平面变化自带1→带3为上升-下降→下降-上升→上升的变化特征。

The Foraminiferal Assemblages Referring to the Climate and Sea Level Change of the North Branch,Yangtze River Estuary Since Late Holocene

The quantitative analysis on 48 foraminifer＇s samples were carried out for Core XL1 in Xinglong sand of the North Branch,the Yangtze River Estuary.It can be found that there are 3 foraminiferal assemblages zones（including 8 foraminiferal assemblages sub-zones）.It was speculated that the sendimentary environment of core XL1 occurred since late Holocene on the basis of the analysis of the sedimentary environment in core XL1 contrasted with core CY in Yonglong sand of Chongming Island.With the comparative analysis of the two Cores CY and XL1 about foraminiferal assemblages characteristic,and referring to the result of vegetable spore characteristic,It was discussed that the characteristic of the climate and sea level change reflected in the core XL1 on Xinglong sand.It opens out that the 3 foraminiferal assemblages zones of core XL1 reflects that the climatic characteristic is warm and a little moist → temperate and a little dry → warm and moist in turn;such fluation of the climate accords with not only the changes of the word climate,but also the changes of the sea level is rise to decline→decline to rise→rise,providing reliable information for reconstruction of plaeoclimate and plateoenvironment.