摘要
Rare earth elements(REEs) can record geologic and geochemical processes. We studied two granitic regolith profiles from different climatic zones in eastern Tibetan Plateau and found that(1)∑ RREEs ranged from119.65 to 275.33 mg/kg in profile ND and5.11–474.55 mg/kg in profile GTC, with average values of205.79 and 161 mg/kg, respectively. ∑RREEs was higher in accumulation horizon and semi-regolith;(2) Influenced by climate, the fractionation of light and heavy REEs(LREEs and HREEs) varied during weathering. The ratio of LREEs/HREEs in pedosphere was higher than semi-regolith in tropical profile;(3) A negative Eu anomaly in both profiles was the result of bedrock weathering. A positive Ce anomaly was observed in all layers of profile ND, and only in the upper 100 cm of profile GTC. This indicates that redox conditions along the regolith profile varied considerably with climate.(4) Normalized by chondrite,LREEs accumulated much more than HREEs; REE distribution curves were right-leaning with a V-type Eu anomaly in both profiles.
Rare earth elements（REEs） can record geologic and geochemical processes. We studied two granitic regolith profiles from different climatic zones in eastern Tibetan Plateau and found that（1）∑ RREEs ranged from119.65 to 275.33 mg/kg in profile ND and5.11–474.55 mg/kg in profile GTC, with average values of205.79 and 161 mg/kg, respectively. ∑RREEs was higher in accumulation horizon and semi-regolith;（2） Influenced by climate, the fractionation of light and heavy REEs（LREEs and HREEs） varied during weathering. The ratio of LREEs/HREEs in pedosphere was higher than semi-regolith in tropical profile;（3） A negative Eu anomaly in both profiles was the result of bedrock weathering. A positive Ce anomaly was observed in all layers of profile ND, and only in the upper 100 cm of profile GTC. This indicates that redox conditions along the regolith profile varied considerably with climate.（4） Normalized by chondrite,LREEs accumulated much more than HREEs; REE distribution curves were right-leaning with a V-type Eu anomaly in both profiles.
基金
funded by National Natural Science Foundation of China(41210004,41603018,41673124 and2013CB956401)
ministry of water resources of People’s Republic of China(201401050)
