构造作用对伊犁盆地南缘层间氧化带砂岩型铀矿床影响的探讨

以构造地质学和水成铀矿理论为指导,从构造运动和构造变形等两方面分析伊犁盆地南缘铀成矿构造地质条件,认为由新构造运动引起的次级构造变动是控制和改造层间氧化带砂岩型铀矿床的主导因素,而且构造作用在伊犁盆地南缘东、西部存在着差异性。西部主要是中新生代次级构造运动造成掀斜使盆地边缘部分地层暴露地表,遭受风化剥蚀,有利于大型铀矿床的形成;东部以断裂和褶皱构造变形为主,不但使地层暴露地表而且使铀重新分配,有利于中小型铀矿床的形成。

Influences of structures on the interlayer oxidation zone sandstone-type uranium deposits on the southern margin of Yili Basin

Based on geology and the theory of hydromorphic origin uranium deposit,structural conditions of uranium formation on the southern margin of Yili Basin are analyzed from two aspects of structural movements and deformation.It is suggested that the subsidiary structures caused by the neotectonic movement are the major factor that control and reform the interlayer oxidation zone sandstone-type uranium deposit,and the differences lie in the tectonics at the eastern and western section on the southern margin of Yili Basin.At the western section,because Mesozoic and Cenozoic strata are tilted by the subsidiary structures,some strata on the margin of the basin outcrop at the surface and suffer from the weathering and erosion,which is favorable for the formation of large size uranium deposits.But at the eastern section,the fault and fold are predominant,outcropping at the surface,cause the redistribution of the uranium,which is favorable for the formation of small size uranium deposits.