伊犁盆地蒙其古尔铀矿床含矿目的层强高岭石化成因  

Genesis of strong kaolinization in ore-bearing sandstone from Mengqiguer uranium deposit,Yili Basin,China

作　　者：刘红旭[1,2] 丁波[1,2] 刘章月[1,2] 张晓[1,2] 潘澄雨[1,2] 

机构地区：[1]核工业北京地质研究院,北京100029 [2]中核集团铀资源勘查与评价技术重点实验室,北京100029

出　　处：《矿物学报》2017年第1期40-48,共9页Acta Mineralogica Sinica

基　　金：国家973计划项目(2015CB453004);中核集团龙腾项目联合资助

摘　　要：蒙其古尔铀矿床品位富、成矿作用复杂等特点在我国现已发现的砂岩型铀矿床中占据着独特的位置。黏土X射线衍射结果显示,蒙其古尔矿床含矿目的层砂体中普遍发育有强烈的高岭石化现象,其高岭石含量占黏土总量的58%~86%。蒙其古尔矿床含矿目的层中有机质及煤系地层中有机质镜质体反射率(Ro)平均值为0.61%,反映该区煤系地层的成熟度整体处于未成熟-低成熟阶段,属于生物生烃阶段。容矿砂岩烃类包裹体的发现证实了目的层本身曾遭受过有机酸性流体的改造。研究认为,沉积成岩过程中有机酸性流体的渗出及成岩期后地表水的渗入叠加改造作用是蒙其古尔矿区含矿目的层砂岩中普遍发育高岭石化的根本原因,煤成气等还原性流体的介入可能与蒙其古尔矿床富大矿体形成关系密切。Mengqiguer uranium deposit takes up a unique position for its high grade and its complex mineralization in all sandstone type uranium deposits. According to the analysis results, strong kaolinization is universal in target stratum of Mengqiguer deposit, and the kaolinite content occupies 58% to 86% of clay minerals. The average of organic matter vitrinite reflectance （Ro） for Mengqiguer deposit is 0. 612, which shows that the maturation of organic matter and coal measure strata is still in immature to low mature in evolutionary stages and biological hydrocarbon-generating stage. Hydrocarbon inclusions were found in ore-bearing sandstone, which indicates that the target stratum corroded by organic acidic liquids derived from the coal measure strata. The results reveal that the additive effects of organic acid-rich fluid exudation during sedimentation-diagenesis stage and surface water infiltration of post-diagenetic stage are the fundamental factors for strong kaolinization in target stratum, and the reducing fluid, such as coal-formed gas, is closely related to formation of rich and large uranium ore body.

关 键 词：蒙其古尔铀矿床 岭石化 有机酸性流体 烃类包裹体 煤成气 

分 类 号：P619.14[天文地球—矿床学]