鄂尔多斯盆地纳岭沟地区铀矿物赋存形式研究及其地质意义

发布时间：2018-08-28 15:38

【摘要】：纳岭沟铀矿床位于鄂尔多斯盆地东北部的伊陕单斜构造区,该区含矿主岩为中侏罗统直罗组下段下亚段。本文通过电子探针、能谱及背散射分析等方法,详细研究了该区目的层砂岩的铀矿物类型及其赋存形式,并对其矿物组合特征及期次等进行了探讨。结果表明纳岭沟地区铀矿物主要为铀石,还有少量的含钛含铀矿物、沥青铀矿、铀钍石等。铀矿物与黄铁矿、蚀变钛铁矿、锐钛矿/白钛石、粘土矿物等密切共生,呈毛刺状或微细柱状产于矿物边缘,或呈粒状产于黑云母解理缝中,另外也见产于碎屑颗粒中。结合电子探针及背散射分析,对蚀变黑云母解理缝中黄铁矿及铀石成因、以及蚀变钛铁矿与铀特殊关系进行了初步探讨。另外该区存在高Y和低Y元素两种铀石类型,沥青铀矿可能为原铀矿物蚀变残留,结合矿物蚀变期次,初步认为该区含铀砂岩至少遭受两期不同成矿流体作用,多源流体耦合成矿可能是砂岩型铀成矿的重要机制之一。
[Abstract]:The Naling Gou uranium deposit is located in the Yishan monoclinal tectonic area in the northeast of Ordos Basin. The main ore-bearing rock in this area is the lower submember of the lower member of the Zhiluo formation of the Middle Jurassic. By means of electron probe, energy spectrum and backscatter analysis, the uranium ore-forming types and their occurrence forms of the sandstone in the target layer in this area are studied in detail, and the mineral assemblages and their secondary stages are also discussed in this paper. The results show that uranium ore in Naling Gou area is mainly uranium stone, and a small amount of titanium bearing uranium ore, asphaltene uranium ore, uranium-thorium ore and so on. Uranium minerals are closely symbiotic with pyrite, altered ilmenite, anatase / white titanite, clay minerals, etc. They occur on the edge of the mineral or in granular form in biotite cleavage joints, and are also found in clastic particles. The origin of pyrite and uranium in altered biotite cleavage joint and the special relationship between altered ilmenite and uranium were discussed with electron probe and backscattering analysis. In addition, there are two types of uranium stone in this area, high Y and low Y elements, and the asphaltene uranium deposit may be the alteration residual of the original uranium deposit. Combined with the mineral alteration period, it is preliminarily considered that the uraniferous sandstone in this area has been subjected to at least two different metallogenic fluids. Multi-source fluid coupling metallogeny may be one of the important mechanisms of sandstone-type uranium mineralization.
【作者单位】：中国地质调查局天津地质调查中心;中国地质调查局天津地质调查中心非化石能源矿产实验室;核工业208大队;
【基金】：国家重点基础研究计划973项目(编号2015CB453006) 国家青年自然科学基金(编号41502195) 中国地质调查项目(编号DD20160127)联合资助
【分类号】：P619.14

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