巴格毛德油页岩中稀土元素特征研究及其地质意义

油页岩中的稀土元素（REE）研究不仅可以用于解决岩石地质成因，提供物质来源信息，而且可以对REE含量进行资源评价，有利于油页岩的综合开发利用，具有重要的理论和现实意义。本研究测试并分析了银额盆地巴格毛德凹陷中生界白垩系下统巴音戈壁组（K1b）巴格毛德油页岩REE地球化学特征，分析结果表明，油页岩中的REE总量（∑REE）为94．8×10^-6～178×10^-6，平均值为126×10^-6，低于其围岩的∑REE；轻、重稀土元素含量比值（∑LREE／∑HREE）为2．60～3．45，平均值为3．10。（La／Yb）w为0．57～1．02，平均值为0．89，表明油页岩中LREE、HREE分异不明显，LREE相对HREE富集，属于LREE低度富集型。Eu表现为明显负异常，Ce表现为微弱的正异常，表明了油页岩形成于还原的古湖泊环境。油页岩样品∑REE与其微量元素的聚类分析结果表明，油页岩中的REE主要来自陆源碎屑沉积。油页岩样品δCe与δEu、δCe与∑REE均无明显的相关关系，表明成岩作用对REE的影响十分有限，研究区油页岩的成岩阶段处于未成熟阶段。

Rare earth element characteristics of Bagemaode oil shale, Inner Mongolia, China

Study on REE of oil shale formation of oil shales. Meanwhile, it may give source information, which is important for understanding the is also useful for the evaluation of REE resources, which contributes to comprehensive utilizations of oil shale. In this study, we analyze the REE concentrations of Bagemaode oil shale in the Bayingebi Formation （K1b）, Bagemaode Depression in the Inner Mongolia, China. The total REE content ranges from 94. 8 ×10^-6 to 178 × 10^-6, with an average of 126 × 10^-6, which is lower than that of the country rocks.∑LREE/∑HREE varies between 2.60 and 3.45, 3.10 in average, （La/Yb）N, 0. 57 and 1.02, 0.89 in average. The data shows slight LREE enrichment. The REE patterns are characterized by markedly negative anomalies of Eu and slight positive anomalies of Ce, which suggest the Bagemaode oil shale was formed in anoxic paleolake environment. Based on the clustering analysis of total and individual REE concentrations, we conclude that the REE in the Bagemaode oil shale generated from territorial clastic deposits. In addition, there is no evident correlation among δCe, δEu, and δREE, suggesting that diagenesis had limited influence on REE concentrations. Thus, we interpret that the diagenesis phase of the Bagemaode oil shale is unmatured period.