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伊犁盆地是发育在晚古生代火山裂陷盆地基础之上的中生代拗陷盆地。中、下侏罗统含煤系是铀矿化赋存的有利部位。由于区内两组控盆控岩构造(NW向和近EW向)活动强度东强西弱,导致沉积环境东部动荡、西部相对稳定。从而使含煤系沉积具有东部粒度粗、厚度小;西部粒度细、厚度大的变化规律。根据沉积相标志的综合分析,首次提出含煤系沉积相模式为冲积扇-扇前辫状河-滨湖三角洲(狭窄)-湖沼相。文中还概述了层间氧化带铀矿化的基本地质特征;分析了盆地铀矿化的南北差异、东西差异及其形成原因;探讨了铀成矿机理;提出了适于地浸的砂岩铀矿的七个地质条件,并据此对盆地铀成矿前景进行了分析,提出四片有利于成矿的远景区。
The Ili basin is a Mesozoic depression basin developed on the basis of late Paleozoic volcanic rift basins. The middle and lower Jurassic coal measures are the favorable sites for uranium mineralization. As the activity intensities of the two groups of controlled basin-controlled rocks in the area (NW direction and near EW direction) are weaker in the east and west, the eastern part of the sedimentary environment is turbulent and the western part is relatively stable. Therefore, coal-bearing sediments have the features of coarse grain size and small thickness in the east; fine grain size and large thickness in the west. Based on the comprehensive analysis of sedimentary facies markers, it is proposed for the first time that the coal-bearing sedimentary facies model is alluvial fan-fan braided river-lake delta (stenosis) -laser phase. The basic geological characteristics of interlayer oxidation zone uranium mineralization are also summarized. The differences between north and south of uranium mineralization in the basin, differences between east and west are analyzed. The mechanism of uranium mineralization is discussed. Sandstone uranium ore Based on this, the prospect of uranium mineralization in the basin was analyzed and four long-term prospect areas favorable to metallogenesis were proposed.