The behaviour of rare-earth elements (REE) during weathering of granites in southern Guangxi, China

Abstract

The behaviour of the rare-earth elements (REE) during the weathering of granites was studied in southern Guangxi, China. Based on the study of the weathering profiles, the soil, weathered and sub-weathered zones are identified with different REE geochemical behaviours through the weathering profiles of granite. The Ce anomalies of the weathering profiles cover a large range of values with most falling between 1.02 and 1.43 in the soil zone and 0.16 and 0.40 in the weathered and sub-weathered zones. Light rare-earth elements (LREE) and heavy rare-earth elements (HREE) are enriched to varying degree in the weathering profiles as compared to host granites. In the soil zone, more HREEs are leached than LREEs, and HREEs are more enriched than LREE in the weathered and sub-weathered zones. It is considered that infiltration and adsorption on clays are two processes controlling the enrichment and formation of REE deposits in the weathering profiles of granite.