不同成因型母质发育土壤稀土元素的地球化学特征分析

Analysis of geochemical characteristics of rare earth elements in soils derived from different parent material types

分析了 1 7种母质发育土壤的稀土元素 (REE)的地球化学特征 ,结果表明 :(1 )基性岩浆岩母质发育土壤的稀土总丰度最高 ,红砂岩者最低 ;(2 )岩浆岩和喷出岩者的 REE科勃尔分布模式仍表现出母岩特征 ,沉积型者则相对平稳 ,但海相沉积型者变异显著 ;(3 )各类母质发育者∑ Ce/∑Y特征值达 3 .5 -4.7,∑ Ce与∑ Y分馏特征明显 ;(4 )砂页岩等 4种母质者δCe正异常 ,火山喷出岩等 3种母质者 δCe相对稳定 ,酸性岩浆岩等 1 0种母质者 δCe负异常 ;紫砂岩母质者 δEu正异常 ,页岩等 3种母质者δEu相对稳定 ,基性岩浆岩等 1 3种母质者 δEu负异常 ;(5 )逐步回归分析表明 ,∑ REE与 Ce、Sm、Dy、Lu,∑ Ce与 Pr、Sm,∑ Y与 Dy、Lu相关显著 ;(6)双重筛选逐步回归分析表明 ,∑ REE、∑ Ce与土壤 Fe2 O3相关极显著 ,∑ Y与土壤 p H值、粉砂粒、物理性粘粒相关显著 ;(7)通过 REE动态聚类分析 。

The geochemical characteristics of rare earth elements (REE) in soils derived from 17 kinds of parent materials were analysed. The results were as follows: (1) The ∑REE of the soils derived from basic igneous parent materials was the highest, that of the soils derived from red sandstone parent materials was the lowest. (2) The REE Kebole distribution modes of the soils derived from magmatic rock and extrusive rock parent materials were similar to their parent rocks; that of deposit type soils were relative steady, that of marine deposit type soil varied obviously. (3) The ∑Ce/∑Y proper values of the all kinds of the soils derived from different parent materials were 3.5-4.7. The characteristic of the fractional distillation between ∑Ce and ∑Y was obvious. (4) δCe of the soils derived from arenaceous shale and three other parent materials was positively anomalous, that of soils derived from extrusive rock and two other parent materials were relatively steady, that of soils derived from acid igneous rocks and nine other parent materials were negatively anomalous; δEu of the soils derived from purple sandstone and three other parent materials was positively anomalous, that of the soils derived from shale and two other parent materials was relatively steady, that of the soils derived from basic igneous and twelve others parent materials was negatively anomalous. (5) Stepwise regression analysis showed the correlations between TRE and Ce, Sm, Dy, Lu; the correlations between ∑Ce and Pr, Sm; and the correlations between ∑Y and Dy, Lu. (6) Double sieving stepwise regression analysis showed the corrections between ∑REE, ∑Ce and Fe 2O 3 in soils were extremely significant, the corrections between ∑Y and soil pH value, silt, physical clay were significant.(7)The soils derived from different parent materials were divided into three types based on their lithological background by REE dynamic cluster analysis.