安溪铁观音茶园垂直剖面土壤中稀土元素的地球化学特征

采集了安溪某茶园一条垂直剖面土壤样(深度160 cm,共16个样),用电感耦合等离子体质谱法(ICP-MS)分析测定了其中的稀土元素含量,研究了剖面土壤中稀土元素的地球化学特征。结果表明:土壤样品中稀土元素总量范围为165.38~229.91 mg/kg,其平均含量高于中国土壤和世界土壤的平均值;土壤中轻重稀土分馏明显,其稀土元素组成特点表现为轻稀土(LREE)富集,重稀土(HREE)亏损,Eu呈负异常,Ce呈正异常;稀土元素的富集因子平均值的分布范围为0.28~1.34,稀土元素均处于无污染或轻微污染。本研究为了解安溪茶园中稀土含量特征提供了基础数据,为现有茶园的治理和后备茶园基地的合理选址提供了科学依据。

Geochemical Characteristics of Rare Earth Elements in the Vertical Profile of Soil of the Tea Garden in Anxi Area, China

A cylindrical sample (160 cm in depth, 16 samples) was collected from a tea garden in Anxi area, China. Contents of REE in soil were determined by using inductively coupled plasma mass spectrometry (ICP-MS) and the geochemical characteristics of REE were also investigated. Results show that content of total REEs ranges from 165.38 to 229.91 mg/kg in the soil core and the average contents of rare earth elements in the vertical profile of soil are much higher than those in China as well as in the world. The fractionation between LREE and HREE is apparent in the whole soil profile. Relative enrichment of LREE and variable HREE of the soil were observed. Ce shows positive anomalies in the process of soil development, whereas Eu is negatively anomalous. Enrichment factors (EF) of REEs analysis suggest that average EF ranges from 0.28 to 1.34.According to EF results, rare earth elements are at the light pollution level or no pollution. The results of this study provide basic data to understand the characteristics of REEs, to improve the existing conditions and to select the backup site for sustainable development of tea garden in Anxi area.