蒙其古尔铀矿床东段富大矿体成因研究

Study on the Genesis of Large-rich Orebody in the Eastern Segment of Mengqiguer Uranium Deposit

蒙其古尔铀矿床是我国重要的可地浸砂岩型铀矿床。文章通过总结蒙其古尔铀矿床东段西山窑组下段矿体空间定位的共有特征,侧重类比富大矿体独有特征,从厚大砂体、强层间氧化作用、多元地球化学障、双向、多期次氧化流体等方面,对研究区富大矿体成因进行了初步总结,总结其成因为:1)厚大砂体是层间氧化流体运移的通道,控制氧化带展布方向和富大矿体空间定位,矿体与砂体厚度呈正相关;特富矿体分布于厚大砂体边部,与内部泥质夹层关系密切,是富大矿体形成的基础条件;2)强层间氧化作用与强还原环境形成的多类型地球化学障叠加作用是形成富大矿体的根本原因;3)双向、多期次氧化流体作用下的地下水水动力系统是形成富大矿体的动力来源。

The Mengqiguer uranium deposit is an important in-situleachable sandstone type uranium deposit in China.By summarizing the common characteristics of large-rich ore body in the spatial positioning of the ore body in the lower member of Xishanyao Formation in the eastern part of Mengqigure uranium deposit,this paper preliminary summarized the genesis of large-rich ore body in the working area in the aspects scale of sand body,strong interlayer oxidation,multiple geochemical barriers,bidirectional and multi-stage oxidation fluids.The genesis was summarized as the following:1)The thick and large sand body is the channel of interlayer oxidation fluid migration,which controls the distribution direction of oxidation zone and the spatial positioning of large rich ore body.The ore body scale is positively correlated with the thickness of sand body;The rich ore body is distributed in the edge of thick large sand body,which is closely related to the inner argillaceous interlayer,and is the basic condition for the formation of rich large ore body.2)Superposition of multiple types of geochemical barriers caused by strong interlayer oxidation and strong reduction environment is the fundamental cause for the formation of large ore bodies.3)The groundwater hydrodynamic system under the action of bidirectional and multi-stage oxidizing fluid is the power source of the formation of large ore bodies.