鄂尔多斯盆地纳岭沟铀矿床后生蚀变成因及其与铀成矿的关系

鄂尔多斯盆地纳岭沟铀矿床是中国近期落实的又一特大型铀矿床,为古层间氧化带砂岩型铀矿床。根据蚀变作用与成矿作用的关系,建立了新的古层间氧化带砂岩型铀矿床后生蚀变分类方法,即将其划分为控矿蚀变、成矿蚀变和保矿蚀变3类。分别从垂向上和平面上分析了后生蚀变的空间分布规律,剖面自下而上整体表现为保矿蚀变-成矿蚀变-控矿蚀变的垂向序列;平面上重点分析了氧化砂体厚度、氧化砂体百分率、氧化砂体底埋深、氧化砂体底标高等参数特征。

The genesis of epigenetic alteration and its relationship with uranium mineralization in the Nalinggou uranium deposit, Ordos Basin

The Nalinggou sandstone-hosted uranium deposit is a large-sized paleo-interlayer oxidation zone sandstone type uranium deposit. According to the study of the relationship between alteration and uranium mineralization, a new classification method for epigenetic alteration in paleo-interlayer oxidation zone sandstone type uranium deposits was established. There are three categories, i.e., ore control alteration, mineralization alteration, and ore-protecting alteration. The spatial distribution of epigenetic alteration was analyzed vertically and horizontally. On cross sections, from the bottom to top, there exists a vertical alteration sequence of ore-protecting alternation, mineralization alteration, and ore control alteration. This paper also discussed distribution characteristics of the thickness of oxidized sandstone, the percentage of oxidized sandstone, the bottom depth of oxidized sandstone, and the elevation of oxidized sandstone bottom.