海南土壤中稀土元素含量及分布特征

THE CONCENTRATIONS AND DISTRIBUTION CHARACTERISTICS OF THE RARE EARTH ELEMENTS (REES) IN SOILS OF HAINAN PROVINCE

对海南四种不同母质来源的土壤样品中的稀土元素含量及分布特征进行了研究,结果表明:除砂岩母质外,海南省其它母质的土壤中稀土元素总量都高于全国土壤、世界土壤和地壳中稀土元素的平均含量;各母质类型土壤中Eu亏损明显。花岗岩上发育的土壤中稀土元素含量最高,总量达419.42mg/kg。砂岩和花岗岩上发育的土壤中LREE相对富集。LREE和HREE在不同母质来源的土壤剖面中的富集、迁移等地球化学行为不完全相同,这说明:土壤发育过程中,稀土元素的含量和分布不仅仅和成土过程、气候及其它地球化学因素有关,而且与母质也有重要的关系,母质往往制约着风化成土过程中稀土元素的地球化学行为。

This paper deals with the concentrations of the rare-earth elements (REE) in soils derived from different kinds of parent materials on the Hainan Island, indicating that the concentrations of the REEs are higher than those of soils in the whole country, the whole world and the Earth's crust except the soil derived from sandstones. All kinds of soils show remarkable negative Eu-anomalies. The concentrations of the REEs in the soils derived from granites are higher than those in other types of soils (434mg/kg). Relative LREE enrichment can be seen in the soils derived from sandstones, granites and shales. The geochemical behaviors of enrichment and mobility of the LREEs and HREEs are not identical. This indicates the concentrations and distribution of the REEs in the soils are determined not only by the climate and the process of soil formation, but also by other factors such as the parent material of the soil, which even can control the most geochemical behaviors of the REEs in the process of soil formation