湘江谷地土壤中稀土元素含量及分布特征

用仪器中子活化法(INAA)测定了湘江谷地土壤(表层)中八个稀土元素(La,Ce,Nd,Sm,Eu,Tb,Yb和Lu),并对其分布特征作了初步探讨。结果表明,该地区土壤中稀土元素平均含量为197ppm,高于世界土壤含量(154ppm),同时也高于我国吐鲁番地区和松辽平原土壤的稀土元素含量;该地区土壤中稀土元素含量的变异系数较大,可达50—66％;该地区四种主要类型土壤中稀土元素含量分布规律为:水稻土>红壤>黄壤>紫色土;球粒陨石归一化后,呈斜率为负值的曲线,主要富集轻稀土元素。

CONCENTRATIONS AND DISTRIBUTIONS OF REE IN THE SOILS FROM XIANGJIANG VALLEY

Eight rare earth elements (REE) including La, Ce, Nd, Sm, Eu, Tb, Yb and Lu in 96 soil samples from Xiangjiang Valley area were determined by instrumental neutron activation analysis(INAA).The distribution characteristics of REE in different soils have been studied. The results showed that the average content of REE in these soils is 197 mg/kg, which is higher than those of the world's soil (154mg/kg) and the soils from arid region and plain area of China. The coefficients of variation of the measured data are quite large (from 0.5 to 0.7). The contents of REE in four major soil types of the area rank as follows: Paddy soil > Yellow soil > Red soil > Purple soil. After normalized using mean values of chondrite, the REE patterns for different great group soils are very similar to those of typical North America Shales with negative slopes but the light REE are rather enriched for this area.