Geochemistry characteristics of rare earth elements in the Permo-Carboniferous Taiyuan Formation coal from Ningdong coalfield at the western margin of Ordos Basin

Taking thePermo-Carboniferous Taiyuan Formation（Fm） coal in Nindong coalfield as the research object to study the geochemistry characteristics of rare earth elements(REE)and discussed its occurrence characteristics and origin, base on the data from X-ray fluorescence spectrometer and plasma mass spectrometer. The result show that: The average content of REE in Permo-Carboniferous Taiyuan Fm coals from Nindong coalfield is 91.91μg/g, which is lower than the average content of 135.89μg/g in China coals. Theobviously negative Eu abnormity, unobviousCe abnormity, La_N/Yb_N, La_N/Lu_N, La_N/Sm_N, LREE/HREE and the REE distribution patternsnormalized by the upper crust all reflect the characteristics of low fractionation of light and heavy REE and relative enrichment of heavy rare earth elements in coals. The REE in coal mainly occurs in clay minerals, which can be verified by the positive correlation between rare earth elements and ash, Si, Al, Na, K. The source, content and occurrence characteristics of REE inPermo-Carboniferous Taiyuan Fm coals from Ningdong coalfield are mainly controlled by the supply of felsic terrigenous clasts, but also affected by local micro-topography, micro-geomorphology and micro-environment, the impact of seawater and diagenesis are limited.