Rare Earth Elements: A Tool for Understanding the Behaviour of Trivalent Actinides in the Geosphere

摘要

Rare earth element (REE) concentrations have been determined in groundwaters, granite and fracture fillings in a restored uranium mine.The granitoids normalized REE patterns of groundwaters show heavy rare earth elements (HREE)-enrichment and positive Eu anomalies. This suggests that the REE are fractionated during leaching from the source rocks by groundwaters. Preferential leaching of HREE would be consistent with the greater stability of their aqueous complexes compared to those of the light rare earth elements (LREE), together with the dissolution of certain fracture filling minerals, dissolution/alteration of phyllosilicates and colloidal transport.