REE Geochemistry in the Laterite Crusts Derived from Ultramafic Rocks:Comparative Study of Two Laterite Profiles under Different Climate Condition
Fu Wei
Huang Xiaorong
Yang Mengli
Lei Liangqi
Niu Hujie
Zhang Yaqian
Abstract：To understand the characteristics and evolution of REE during the process of the ultramafic laterization under different climate conditions,two outcrops Kolonodale in Indonesia and Yuanjiang in China are chosen for comparision.It is found that the contents of REE from the laterite crusts are higher than those from the bed rocks in both places (enrichment factor being 44.21 and 236.19 respec-tively).The indices of differentiation between the LREE and HREE decrease with profile downward toward,and the indice of Ce anom-aly shows a shift from the positive Ce anomaly in the upper segment to negative Ce anomaly in the lower part.The difference between the two profiles lies in the distribution of the highest REE enriched segment.The laterite layer represent the most REE enriched for the Yuanjiang,whereas the saprolite layer for the Kolonodale.The evaluation of the mass balance shows remarkable migration and differen-tiation of REE in the ultramafic laterization process,which were constrained effectively by the pH environmentand organic matter (O.M.).The results indicate that climate have had great influence on the geochemical evolution of REE during the ultramafic lateriza-tion.Under the rainforest climate condition,the REE from the Kolonodale originates mainly from the basal rocks and has experienced intensive redistribution during the laterization;whereas the REE from the Yuanjiang has a mixed source stemming from both the parent rock and aeolian sediment,and it has been through only slight redistribution during the laterization.
Keywords：rare earth elementlaterite crustultramafic rockclimate conditiongeochemistry
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：17( 716-732 )