The examination of the sedimentary characteristics of the uranium reservoirs is considered to be the orehunting prerequisite for the sandstone-type uranium deposits.Reported here are the distribution and scales of the uranium reservoirs and division of sedimentary facies in the Baoligentaohai region,Tengger depression in terms of coalfield geophysical data and regional geology,and prediction of uranium potential on the basis of uranium source,structure,radioactivity logging and ground gamma spectrometry.The uranium-impounding sandstones in the Saihan Formation are well developed and generally oriented to SE-NW.The lower member of the Formation has a total sandstone thickness of 120-200 m in the braided delta plain subfacies of the braided delta facies,and consists of five normal graded depositional cycles.The upper member of the Formation has a total sandstone thickness of 50-90 m in the braided river facies and consists of two normal graded depositional cycles.The study area is characterized by abundant uranium sources,favourable structures and sedimentary facies.The potential favourable areas comprise the braided distributary channel sandstones near the flood plain or interdistributary bay,and 5th and 7th depositional cycles.%本文利用煤田钻孔资料,结合区域地质特征,首次对研究区铀储层砂体展布及规模,以及铀储层沉积相带进行精细刻画.在此基础上,结合铀源、构造、煤田钻孔放射性测井和地面伽马能谱测量等因素,对研究区铀成矿前景进行预测.研究发现,赛汉组铀储层砂体发育,总体呈南东—北西向展布.赛汉组下段砂体累积厚度120 ～ 200m,发育辫状河三角洲相,其中辫状河三角洲平原分布广泛,由5个正粒序沉积旋回构成;赛汉组上段砂体累积厚度50～90m,发育辫状河相,由2个正粒序沉积旋回构成.研究区具有丰富的铀源、有利的构造背景及沉积相带,砂岩型铀成矿有利区平面上位于辫状(分流)河道砂体边缘靠近泛滥平原或分流间湾的部位,垂向上位于⑤号和⑦号沉积旋回.
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