黔西地区晚二叠世宣威组一段底部富稀土岩系不同岩性段地球化学特征及成矿物质来源还不清楚。文章通过对黔西恰西地区典型剖面开展主量、微量及稀土元素地球化学分析，对富稀土岩系不同岩性段地球化学特征及成矿物质来源进行了探讨。结果显示，富稀土岩系由下往上可划分为铁质岩段、铝质岩段及碎屑岩段，其中，铝质粘土岩段稀土含量最高，最高可达0.76%。富稀土岩系以SiO2、Al2O3、FexOy、TiO2为主，四者含量之和在83.93%~87.24%之间；Cs、Rb、Ba、V等大离子亲石元素亏损，Zr、Hf、Nb、Ta等高场强元素稳定；稀土配分模式均显示为右倾型，不同岩性段具体表现为：铁质岩段轻、重稀土分异中等，δCe无异常，δEu显示弱负异常；铝质岩段轻、重稀土分异程度大，δCe、δEu均显示负异常；碎屑岩段轻、重稀土分馏中等、δCe为弱正异常、δEu为负异常。根据样品ICV值、La/Sc-Co/Th 图解及稀土配分模式综合判断，铝质粘土岩段与碎屑岩段物源主体为剥蚀—搬运—沉积的中酸性火山岩（并非火山灰），铁质岩段物源为近源玄武岩。

Geochemical characteristics and sources of ore-forming material of different lithological sections of the rare earth element (REE)-rich rock series at the base of the first member of the Late Permian Xuanwei Formation in the western Guizhou region are still unclear. This study conducts geochemical analyses of major, trace, and REEs of typical profiles in the western Guizhou and Qixi regions, and explores the geochemical characteristics and sources of ore-forming material of different lithological sections of REE-rich rock series. The results show that the REE-rich rock series can be divided into iron rock section, aluminum rock section, and clastic rock section from bottom to top. Among them, the aluminum clay rock section shows the highest rare earth content, up to 0.76%. The REE-rich rock series is mainly composed of SiO2, Al2O3, FexOy, and TiO2 with a total content of 83.93% to 87.24%; Large ion lithophile elements such as Cs, Rb, Ba, V are depleted, while high-field strength elements such as Zr, Hf, Nb, Ta are stable; The REE distribution patterns are all displayed as right dipping with different lithological sections being characterized by moderate differentiation of light and heavy REEs in the iron rock section, no δCe anomalies, and weak negative δEu anomalies; The degree of differentiation between light and heavy REEs in the aluminum rock section is significant, showing negative δCe and δ Eu anomalies; The light and heavy REE fractionation in the clastic rock section is moderate with a weak positive δCe anomaly and a negative δ Eu anomaly. Based on the ICV values of the samples, La/Sc-Co/Th diagrams, and REE distribution patterns, it is determined that the main sources of the aluminum clay rock section and the clastic rock section are moderately acidic volcanic rocks (not volcanic ash) that were eroded, transported, and deposited, while the source of the iron rock section is nearby basalts.