Behavior of rare earth elements in granitic profiles, eastern Tibetan Plateau, China

• Published in: Acta geochimica 2017-09, Vol.36 (3), p.552-555
• Main Authors: Cui, Lifeng, Zhao, Zhiqi, Liu, Congqiang, Xu, Sheng, Liu, Taoze, Tu, Chenglong, Ding, Hu
• Format: Article
• Language: English
• Subjects: Bedrock; Climate; Climatic zones; Earth; Earth and Environmental Science; Earth Sciences; Fractionation; Geochemistry; Minerals; Neodymium; Original Article; Oxidoreductions; Pedosphere; Plateaus; Profiles; Rare earth elements; Regolith; Rocks; Stone; Trace elements; Tropical climate; Weathering; 中国; 地球化学过程; 氧化还原条件; 花岗岩风化壳; 行为; 西藏高原; 轻稀土元素; 重稀土元素
• ISSN: 2096-0956; 2365-7499
• DOI: 10.1007/s11631-017-0234-7

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.