伊犁盆地南缘侏罗系沉积相对铀成矿的控制作用  

Sedimentary Facies and It s Controlling to Uranium Deposit of Jurassic at the Southern Margin of Yili Basin

作　　者：邱余波[1] 罗星刚[1] 张磊[1] 苗辰若 李刚 QIU Yu-bo;LUO Xing-gang;ZHANG Lei;MIAO Chen-ruo;LI Gang(Geologic Party No.216,CNNC,Urumqi 830011,China)

机构地区：[1]核工业二一六大队,乌鲁木齐830011

出　　处：《科学技术与工程》2022年第31期13672-13679,共8页Science Technology and Engineering

基　　金：中国核工业地质局铀矿地勘项目(202205)。

摘　　要：沉积相是砂岩型铀矿的重要控矿因素,对含矿流体的富集和成矿至关重要。以不同勘查阶段所收集的钻孔资料为依据,对伊犁盆地南缘不同含矿层位的沉积环境和沉积微相进行全面的分析和研究。在此基础上,根据研究区各含矿层位层间氧化带发育特征,结合铀矿发育的其他成矿地质条件,系统地研究和分析沉积环境和沉积微相与铀成矿的关系。研究表明,沉积相对砂岩型铀矿的控制作用主要表现为沉积相的类型决定铀成矿的潜力和规模,而沉积微相控制着铀矿体的形态和空间展布。在伊犁盆地南缘扇三角洲沉积最有利于铀成矿的发育,其次是河流相沉积,冲积扇相的铀成矿潜力相对较差,但是在局部地段仍有一定的成矿能力。稳定的河道砂体中出现的泥质夹层以及稳定出现的泥质夹层在局部地段的缺失对铀成矿的影响均很大;扇三角洲平原发育的铀矿体较扇三角洲前缘品位高,规模大;由沉积微相的变化所引起的砂体厚度、粒度的变化,是影响铀矿体形态和矿化品位的主要原因。Sedimentary facies is an important ore controlling factor of sandstone type uranium deposit,which is very important for the enrichment and mineralization of ore bearing fluid.Based on the borehole data collected in different exploration stages,the sedimentary environment and sedimentary microfacies of different ore bearing horizons in the southern margin of Yili basin were comprehensively analyzed and studied.On this basis,according to the development characteristics of interlayer oxidation zone of each ore bearing horizon in the study area,and combined with other metallogenic geological conditions of uranium deposit development,the relationship between sedimentary environment,sedimentary microfacies and uranium mineralization was systematically studied and analyzed.The study shows that the controlling of sedimentary relative to sandstone type uranium deposits was mainly that the type of sedimentary facies determined the potential and scale of uranium mineralization,and sedimentary microfacies controlled the shape and spatial distribution of uranium ore bodies.In the southern margin of Yili basin,fan delta deposition was the most conducive to the development of uranium mineralization,followed by fluvial facies deposition.The uranium metallogenic potential of alluvial fan facies was relatively poor,but there was still a certain metallogenic capacity in some sections.The occurrence of argillaceous intercalation in stable channel sand body and the absence of stable argillaceous intercalation in local sections had a great impact on uranium mineralization.The uranium ore body developed in fan delta plain was higher in grade and larger in scale than that in fan delta front.The change of sand body thickness and particle size caused by the change of sedimentary microfacies was the main reason affecting the shape and mineralization grade of uranium ore body.

关 键 词：伊犁盆地南缘 沉积相 砂岩型铀矿 控矿作用 

分 类 号：P512.2[天文地球—地质学]