鄂尔多斯盆地砂岩型铀矿床地球化学特征及其地质意义

Geochemical Features of Sandstone-Type Uranium Deposits in the Ordos Basin and Their Geological Significances

本文在系统的取样分析基础上，详细研究鄂尔多斯盆地砂岩型铀矿的稀土、微量元素地球化学特征，分析研究了鄂尔多斯盆地砂岩型铀矿富集成矿的机理及多种能源共存的内在联系，从而进一步探讨盆地型多种能源富集成藏（矿）的潜在的规律。高精度ICP～MS分析表明：鄂尔多斯盆地砂岩型铀矿REE总体特征为轻稀土富集，重稀土亏损；EREE在36．7～701．8μg／g之间变化，泥岩EREE总体高于砂岩，Y含量都比较高；Eu异常差异明显，在0．3～2．5内变化。微量元素Rb、U、La、Ce、Ph和Pr呈特别明显正异常，其中U含量在0．6～2204μg／g之间，U的富集和一些微量元素如Ti、V、Zr、Mo、Au等相关，本研究对该区铀矿质沉淀和富集规律的认识具有理论意义。

On the basis of analyses of trace elements and REE from the sandstone-type uranium deposits in the Ordos Basin, the genesis of multiple energy resources and the formation of different ore deposits have been discussed in this paper. The high precision ICP-MS analyse presents that the total REE amount ranges from 36.7 to 701.8 μg/g, manifesting that the contents of REE in mudstone samples is commonly higher than those of sandstone samples. The distribution patterns of the sandstone-type uranium samples characterize REE as enrichment in the light REE and depletion in heavy REE, showing the high Y abundance and abnormity of Eu between 0.30-2.5. The U abundances are 0.6~2204 μg/g, some strong correlation between U enrichment and the related elements, such as Ti, V, Zr, Mo, Au has been revealed by this study. This study presents a geochemical basis for understanding the relationships between U enrichments and other related elements.