巴音戈壁盆地塔木素砂岩型铀矿成矿地质特征及成因讨论

Discussion on the Genesis and Metallogenic Geological Characteristics of Sandstone-type Uranium Deposit in Tamusu,Bayingebi Basin

塔木素铀矿床是巴音戈壁盆地最大的砂岩型铀矿床,前人对其成因类型尚未形成统一认识。通过塔木素砂岩型铀矿床成矿地质特征、铀成矿与沉积相关系、铀的存在形式分析及铀成矿年龄探讨,指出矿床蚀变作用主要表现为还原蚀变、古层间氧化蚀变和热流体蚀变3大类,热蚀变在该矿床中广泛发育;铀存在形式以铀矿物(沥青铀矿、铀石)和吸附形式为主;铀矿化受扇三角洲前缘沉积相与NE向贯通性断裂联合控制;提出了同生沉积成矿作用、古层间氧化成矿作用和热叠加成矿作用等3次成矿作用,成因类型为复成因类型。

The Tamusu uranium deposit is the biggest sandstone type uranium deposit in Bayingebi Basin.However,previous researchers have not reached an agreement on the origin of this deposit.Metallogenic geological characteristics,the relationship between mineralization and sedimentary facies,existing forms of uranium and mineralization age of the Tamusu uranium deposit are discussed in this paper.Mineralization alterations can be divided into three types as follows:reduction alteration,paleo-interlayer oxidation and thermal fluid alteration,which are widely developed in Tamusu.Uranium mineral,which mainly contains pitchblende and coffinite,and adsorption form are the main existing forms of uranium.Mineralizations is controlled by two factors,fan delta front sedimentary facies and NE trending fault.Multiple mineralization was proposed as syngenetic sedimentary,paleo-interlayer oxidation and thermal fluid mineralization.The genetic type of the Tamusu uranium deposit is polygenetic.