摘要
为研究宁都盆地典型脐橙园土壤稀土元素地球化学特征,在宁都盆地内共采集30组土壤样品,对REE组成特征、配分模式、参数特征、Eu亏损原因进行分析和讨论。结果表明:土壤样品总稀土含量平均值为346.16 mg·kg^(-1),分别是江西土壤稀土背景值、中国南方红土土壤稀土平均值、中国土壤背景值、北美页岩值、地壳值含量的1.64倍、1.97倍、1.84倍、1.85倍、1.83倍。园内所有样点配分曲线均呈现出右倾的几何形态,∑Ce/∑Y平均值为4.26,显示出土壤中轻稀土相对富集的特点,具有明显的Eu负异常。(La/Yb)_(N),(Gd/Yb)_(N)参数值表明轻稀土元素具有更为显著的分馏作用。δCe,δEu计算结果显示,Ce负异常点主要集中在基岩岩性为花岗岩的土壤中;30组样品Eu则全部呈现出明显的负异常,表明区内土壤具有共同的陆源属性,以酸性岩为主,与区内大面积分布花岗岩相一致。土壤中Eu亏损的主要原因是成土母质存在一定的亏损及土壤发育过程中Eu发生氧化还原反应淋失产生的亏损叠加。La/Yb-∑REE图解显示白垩纪砂岩、砾岩基岩区土壤7组样点全部落在花岗岩岩区,表明白垩纪砂岩、砾岩源岩全部来自花岗岩且物源稳定。
In order to study the geochemical characteristics of rare earth elements(REEs)in the soil of typical navel orange orchard in Ningdu Basin,we collected 30 soil samples in Ningdu Basin for REE content analysis.The results showed that the average total concentration of rare earth elements in the soil were 346.16 mg·kg^(-1),which was 1.64 times,1.97 times,1.84 times,1.85 times and 1.83 times of the background value of Jiangxi soil,the average value of red soil in southern China,the background value of Chinese soil,the North American shale value and the crust value.The curves of all samples sites in the orchard showed a right-leaning geometric shape,and the average value of∑Ce/∑Y was 4.26,indicating that light rare earths in the soil were relatively enriched,with obvious Eu negative anomalies.(La/Yb)_(N) and(Gd/Yb)_(N) parameters indicated that the fractionation of light rare earth elements were more significant.The calculation results ofδCe andδEu showed that the negative anomalies ofδCe were mainly concentrated in the soils with granite bedrock.All the 30 groups of Eu samples showed obvious negative anomalies,indicating that the soils in the area had common terrigenous properties,and were dominated by acid rocks,which was consistent with the large area of granite.The main reasons for the loss of Eu in the soil are the depletion of soil-forming parent material and the superposition of the loss caused by the leaching loss of Eu in the oxidation-reduction reaction during soil development.The La/Yb-∑REE diagram showed that all 7 soil sample points in the Cretaceous sandstone and conglomerate bedrock area fell in the granite rock area,indicating that the source rocks of the Cretaceous sandstone and conglomerate were all from granite and the provenance was stable.
作者
张智印
刘雪松
魏建朋
刘金巍
Zhang Zhiyin;Liu Xuesong;Wei Jianpeng;Liu Jinwei(Center for Hydrogeology and Environmental Geology,China Geological Survey,Baoding 071051,China)
出处
《中国稀土学报》
EI
CAS
CSCD
北大核心
2022年第3期523-532,共10页
Journal of the Chinese Society of Rare Earths
基金
中国地质调查局地质调查项目(DD20179303)资助。
关键词
宁都盆地
脐橙园
稀土元素
Eu负异常
花岗岩
Ningdu Basin
navel orange orchard
rare earth elements
Eu negative anomaly
granite rock
