内蒙古东胜地区侏罗系砂岩铀矿体与煤层某些关联性

金属成矿与有机成藏的关联性是成藏成矿动力学研究的重要课题,东胜砂岩铀矿体与煤层或煤层气是何种关联尚不清楚。文中以多年勘探事实为基础,研究表明,东胜铀矿区铀矿体与煤层平面位置重叠或相近,剖面中铀矿体上下均有煤层,铀矿体与煤层垂距2～15m,两者厚度变化相互响应,铀矿体与煤层具有内在关联性。铀储层酸解烃类主要是CH4,与来自煤层的煤层气主成分一致,铀储层中从砂岩铀矿石,到铀矿化砂岩,再到无铀矿化砂岩,酸解烃类含量依次(CH4分别为569.43μL/kg、174.93μL/kg、156.12μL/kg)降低,铀矿化与煤层气内在关联明显。煤层、尤其是由它产生的煤层气是铀储层中铀矿物沉淀和成矿的重要还原剂,煤层及其厚度的变化可以作为本地区砂岩铀矿体勘探的有机质标志。

The correlation between sandstone uranium ore-body and the coal bed in Jurassic System,Dongsheng,Inner Mongolia

Much more attention has been paid to the relationship of the metallogenesis and the organics accumulation formation.The relationship between the uranium ore-body in sandstone and the coal bed in Dongsheng uranium ore district,Ordos Basin,is still unknown.According to many years of exploration,the paper suggests that the plan location of the uranium ore-body is overlapping or near that of the coal bed in Dongsheng uranium ore district.There are coal beds over or under the uranium ore-body in the section,and the vertical distance between them is 2-15m.The depth changes of the uranium ore-body respond well to that of the coal beds,and there are some inner relationships between the uranium ore-body and the coal bed.The acidolysis hydrocarbon from the uranium-bearing bed is CH4,the same as that in the coal bed gas.The mean content of the acidolysis hydrocarbon is 569.43 μ L / kg in the uranium ore,174.93 μ L / kg in the uranium-bearing sandstone and 156.12 μ L / kg in non-uranium sandstone.The coal bed,especially the coal bed gas,is an important reductant during the uranium mineralization in Dongsheng uranium-bearing bed,and the coal bed and its depth changes may serve as exploration indicators for the sandstone-type of uranium deposits.