二连盆地中东部含铀古河谷构造建造及典型矿床成矿模式研究

发布时间：2018-05-27 19:31

本文选题：地质学 + 赛汉组古河谷　；参考：《矿床地质》2017年01期

【摘要】：二连盆地为中国北方重要的聚煤沉积盆地,同时也发育赛汉组古河谷,古河谷在盆地内呈北东向带状展布,河谷内发育巴彦乌拉、赛汉高毕及哈达图等多个铀矿床。铀矿床具有"同河谷多矿床、同河谷多类型"的特点。作者通过对含铀古河谷构造-建造的研究,将赛汉组古河谷与铀成矿有关的构造演化划分为6个阶段。沉积前断陷期构造形成了古河谷建造沉积的带状谷地;断坳转换期湖相沉积的灰色泥岩,为铀成矿间接提供了还原物质;坳陷期沼泽化沉积,为铀成矿提供了直接还原介质;赛汉组上段热-重力沉降期河流、辫状河三角洲沉积,形成主要的铀储层。挤压隆升剥蚀期,受构造掀斜抬升,影响了成矿作用的类型及规模;成矿后期的热沉降期,导致新一轮的沉积充填,起到保矿的作用。通过对赛汉组沉积体系、砂分散体系等特征的研究,发现下白垩统赛汉组下段沿短轴方向主要发育冲积扇-扇三角洲-湖沼沉积体系,长轴方向发育辫状河三角洲-湖沼沉积体系。赛汉组上段主要发育河流沉积体系,砂体较发育,沿古河谷呈朵状、带状分布,矿床主要产于赛汉组上段古河谷砂体内。建立了赛汉组古河谷内典型矿床的矿床成矿模式,将赛汉组古河谷的矿床成矿模式划分为巴彦乌拉潜水-层间氧化式、赛汉高毕潜水氧化式及哈达图层间氧化式。
[Abstract]:The Erlian basin is an important coal-accumulation basin in northern China, and also developed the ancient valley of the Saihan formation. The ancient valley is distributed in the basin in the north-east direction, and there are many uranium deposits in the valley, such as Bayan Wula, Saihangoby and Hadattu, and so on. Uranium deposits are characterized by multiple deposits in the same valley and many types in the same valley. Based on the study of the tectonic-formation of the uranium-bearing paleo-valley, the tectonic evolution related to uranium mineralization in the ancient valley of the Saihan formation is divided into six stages. The tectonics formed the belt valley of paleo-valley formation before sedimentation, the grey mudstone deposited in lacustrine facies during fault-depression transformation period, which provided the reducing material for uranium mineralization indirectly, and the marsh deposit in depression period provided direct reduction medium for uranium mineralization. The braided river delta deposits in the upper member of the Saihan formation, forming the main uranium reservoir. The type and scale of mineralization are affected by the uplift and uplift of the structure during the extrusion uplift and denudation period, and the thermal subsidence period in the late metallogenic period leads to a new round of sedimentary filling, which plays the role of ore protection. Based on the study of the sedimentary system and sand dispersion system of the Saihan formation, it is found that the alluvial fan, fan delta and lake-marsh sedimentary systems are mainly developed along the short axis in the lower part of the Lower Cretaceous Saihan formation. The braided river delta-lake marsh sedimentary system is developed along the long axis. The upper member of the Saihan formation mainly developed a fluvial sedimentary system with a relatively developed sand body and distributed along the ancient valley in the shape of flowers and bands. The deposit mainly occurred in the sand body of the ancient valley of the upper part of the Saihan formation. A metallogenic model of typical deposits in the Guhe Valley of the Saihan formation has been established. The ore-forming model of the ancient valley of the Saihan formation can be divided into Bayan Wula-interlayer oxidation type, Saihangobe oxidation type and Hadatou interlayer oxidation type.
【作者单位】：吉林大学地球科学学院;核工业二0八大队;
【基金】：中国地质调查局地质调查项目整装勘查区基础地质研究(编号:12120114076601) 内蒙古二连盆地中西部铀矿资源远景调查(编号:DD2016013607) 中国核工业地质局二连盆地铀矿调查与勘查项目(编号:201702)联合资助成果
【分类号】：P619.14

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