湘江株州至洞庭湖口江段现代沉积速率研究

本文采用沉积物剖面上的韵律与冲刷面特征,微量元素垂向分布特征和~(210)Pb 测龄法三者相结合的方法,测定了湘江株州至洞庭湖口河流沉积物的沉积速率。该江段不同地点的沉积速率在不同时期是各异的,但20年来总的年平均速率是4.5—5.5cm/年,略高于洞庭湖口的沉积速率(4.2cm/年)。

RESEARCH ON MODERN SEDIMENTATION RATE OF XIANG RIVER IN THE REACH BETWEEN ZHUZHOU AND THE MOUTH OF LAKE DONGTING, HUNAN PROVINCE

First this paper, discribed briefly the characteristics of the component and structure of the sediments sampled from the river reach between zhuzhou and the mouth of Lake Dongting of Xiang River, then discussed the sedimentation rate of Lake Dongting as determined by 210Pb method, and at last gave out the 1968,1973, 1979 and 1982 isotime lines of the fluvials through the studies of the distributive characteristics of trace elements and analyses of the structure of the sedimentary profiles at different localities of the reported river reach. The final result shows that the sedimentation rate of Xiang River was 4.5-5.5 cm/yr.over the past 20 years, which was faster than the rate of 4.2 cm/yr. of Lake Dongting during the same time. It is suggested that through isotopic dating and the determination of the distribution of trace elements and the sedimentary structure of the fluvial sediments, the sedimentation rate can be derived.