伊犁盆地洪海沟地区中侏罗统头屯河组砂岩储层岩石学特征及其与铀富集关系研究

Study on Sandstone Petrologic Feature of the Toutunhe Formation and Its Controls on Uranium Enrichment in Honghaigou Area,Yili Basin

洪海沟地区位于伊犁盆地南缘,中侏罗统头屯河组是该区砂岩型铀矿的主要含矿层位,具有良好的产铀前景。通过野外地质调查、钻孔取样、显微镜下观察、扫描电镜和α径迹蚀刻等方法,对该地区砂岩的岩石学特征、铀的分布规律进行研究,分析成岩作用对铀分布的影响。研究发现,目的层砂岩具有近物源的特点,为铀成矿提供充足物源;成岩矿物有黏土矿物;铀矿分布于与黄铁矿密切共生;后期氧化流体运移是铀成矿的主要作用。

Honghaigou area is located in the southern margin of Yili Basin,the Toutunhe Group of Middle Jurassic is the main stratigraphic position of sandstone type uranium deposit in this area,and has a good prospect of the formation of uranium ore. Petrological characteristics of the sandstones in the area. The uranium distribution was studied by the methods of field geological survey,sampling at the drilling,microscope observation,electron microscope（ SEM） scanning and α track etching. The influence of diagenesis on the distribution of uranium were analyzed The results found that the sandstone has the characteristics of near source. Diagenetic minerals are clay minerals. The uranium deposits are closely associated with pyrite. The mineralization in sandstone is controlled by diagenesis. Later stage oxidizing fluid migration is the main function of uranium mineralization.