长江和黄河入海沉积物不同粒级组分中稀土元素的比较  

COMPARISON OF RARE EARTH ELEMENT COMPOSITIONS IN DIFFERENT GRAIN-SIZE FRACTIONS OF SEDIMENTS FROM THE YANGTZE AND YELLOW RIVERS AND THE SEA

作　　者：乔淑卿[1] 杨作升[1] 

机构地区：[1]中国海洋大学海洋地球科学学院

出　　处：《海洋地质与第四纪地质》2007年第6期9-16,共8页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(90211022)

摘　　要：为探索区分黄、东海陆架沉积物中来自长江和黄河源的有效替代性指标，从长江和黄河河口区各取3个沉积物样品作为长江和黄河入海沉积物的端元样品。研究结果表明：长江和黄河沉积物不同粒级组分中REE的变化范围分别为145．49～256．77μg／g和121．22～135．56μg／g，随粒度由细变粗分别呈下倾的“双峰”型分布和倒“S”型分布；长江沉积物中REE约为黄河的1．5倍，最低值比黄河的最高值高出20％；8～16μm和2～4μm是凸显长江和黄河沉积物稀土元素差异的敏感粒级，REE、LREE／HREE和（La／Yb）n等稀土元素特征参数在这两个粒级组分中差异明显。本次实验结果大幅度地提高了两条河流REE差异的灵敏度和可信度，为建立区分长江与黄河入海沉积物物源实用的有效指标提供了可能。To seek effective proxies for discriminating the Yangtze River sediments from the Yellow River sediments in the Yellow and East China Seas, six sediment samples were taken from the Yangtze and Yellow River mouth areas as end members. 463 μm fractions of the bulk samples were separated at intervals of 1Ф,and then concentrations of rare earth elements （REE） in these sediments were measured by Inductively Coupled Plasma-Mass-Spectrometry （ICP-MS）. The results show that： （1）The ranges of REEs in sediments from the Yangtze and the Yellow Rivers are 145.49-256.77 and 121.22-135.56 μg/g respectively,and the REE distributions with increasing grain sizes show bi-modal type for the Yangtze River sediments, and inverse ＂S＂ for the Yellow River sediments. （2） REE concentrations in the Yangtze River sediments are relatively higher. REE values are 1.5 times of those in the Yellow River sediments, and the lowest REE in the Yangtze River sediments is 20% higher than the highest value in the Yellow River sediments. （3） 2-4 and 8-16μm are the sensitive grain-size fractions to differentiate the Yangtze and Yellow River sediments, and diagnostic parameters of REEs such as REE, LREE/HREE and （La/Yb）n are clearly different in these two fractions of the Yangtze and Yellow River sediments. The result largely enhanced the difference of REE in sensitivity and reliability in the two rivers＇ sediments, which makes the usage of REE as an effective provenance proxy become possible.

关 键 词：沉积物 稀土元素(REE) 粒级 长江 黄河 

分 类 号：P736.4[天文地球—海洋地质]