伊犁盆地南缘含矿砂体特征与铀成矿关系研究

摘要

Material composition, thickness, sedimentary features and permeability of ore-bearing sandbody are indispensable factors for interlayer oxidized zone sandstone type uranium mineralization. Through systematic analysis of ore-bearing sandbody thickness varia⁃tion and sedimentary microfacies features at mid-west sector south margin of Ili Basin, considered that under different sedimentary con⁃ditions, different ore-bearing sandbody features, sandbody pastes, clay mineral contents, and amount, thickness of lenticular argilla⁃ceous barrier in sandbody caused different ore-bearing host rock reducing capacity and adsorptivity. Diversity of groundwater seepage models has caused diversity of mineralization models at south margin of Ili Basin. Study on sandbody thickness has found the pay grade uranium orebodies are mostly developed at sandbody thickness turning position, vertically lithological interface turning from coarse to fine (redox interface).%含矿砂体物质成分、厚度、沉积特征与渗透性，是层间氧化带砂岩型铀矿成矿不可或缺的因素。通过对伊犁盆地南缘中西段含矿砂体的厚度变化、沉积微相特征的系统分析。认为不同沉积条件下，含矿砂体特征、砂体泥质与粘土矿物含量及砂体中透镜体泥质隔挡层的数量、厚度不同，导致含矿主岩的还原能力、吸附能力的不同。地下水渗流模式的多样性，使得伊犁盆地南缘的成矿模式具有多样性。对砂体厚度研究发现，工业铀矿体大都发育在砂体厚度变化的转折部位，垂向上岩性由粗转细的界面（氧化-还原界面）是工业铀矿体易于富集的场所。