Absorption and Fractionation of Rare Earth Elements by Plants: a Comparative Study of Plants in Diverse Geological Contexts

Abstract

This work investigates the behavior of REE in some plant species in relation to the concentration levels of theseelements in the substratum, independent of the metabolic and physiological specifi cities of each type of plant and of thenature of the geochemical environment. REE concentrations of leaf ashes determined by ICP-MS e ICP-3500 techniqueshad been compared with the concentrations of the soil or rock samples of different geologic contexts such as carbonatitic,syenitic and ultramafi c environments. In the syenitic environment the REE patterns in leaf ash are similar to those of thewhole rock, reproducing the LREE enrichment. In the ultramafi c environment the leaf ash contents are higher than thoseof soils, with REE patterns displaying the W-type tetrad effect. In the lateritic covering of the carbonatite leaf ash patternshave lower REE contents and lack positive Ce anomalies. The results show that the diverse species refl ect the REE patternsof the substratum with some variations, such as the tetrad effect, resulting from the fractionation of the elements of theseries by the plants.

Keywords

• Rare earth elements
• Plant species
• Fractionation
• Syenite
• Ultramafi c rocks
• Carbonatite