长江与汉江现代沉积物元素组成分析

Analysis on elementary composition of sediments in the Yantze River and the Hanjiang River

长江与汉江表层沉积物常量及微量元素组成特征分析表明,长江沉积物的常量化学组分中CaO、MgO相对较汉江高,汉江沉积物中Fe2O3、Al2O3、K2O相对较长江高;汉江沉积物的微量化学组分中Cr+Ni、Mo、As、Sb、F等元素相对长江高;长江沉积物Cd的赋存形式以离子交换态和碳酸盐态为主,汉江沉积物Cd的赋存形式以残余态为主。长江沉积物与汉江沉积物组成的差异是由其源区表壳岩系决定的,前者呈现高CaO、MgO,并呈碱性(pH:8.02)的特点,而后者相对富Fe2O3,并呈中性(pH:6.8)。

The analysis show that： the sediments in the Yangtze River are relatively richer in some major elements such as CaO and MgO than the Hanjiang River＇ s, while the sediments in the Hanjiang River have comparatively higher major elements such as Fe2O3, Al2O3, K2O than the Yangtze River＇ s; the trace elements of sediments in Hanjiang River including Cr and Ni, No, As, Sb as well as F are higher than the Yangtze River＇ s; Cd of the sediments in the Yangtze River exists in forms of ion exchange and static carbonate, which in the Hanjiang River is in residual form. The difference of sediments in the Yangtze River and the Hanjiang River is caused by the surface rocks in the source area. The Yangtze River sediments have high CaO and MgO in contents, appearing as alkali （pH： 8.02）, and the Hanjiang River sediments are rich in Fe2O3 with litmusless feature（pH： 6.8）.