新疆砂岩型铀矿床中稀土元素地球化学特征对比分析——以伊犁盆地铀矿床与巴什布拉克铀矿床为例  

Comparative Analysis of Geochemical Characteristics of Rare Earth Elements in Sandstone Type Uranium Deposits in Xinjiang——Taking the Ili Basin Uranium Deposit and Bashbulak Uranium Deposit as Examples

作　　者：张映宁 Zhang Yingning(The 216th Party of CNNC,Urumqi,China)

机构地区：[1]核工业二一六大队,新疆乌鲁木齐

出　　处：《科学技术创新》2024年第1期24-28,共5页Scientific and Technological Innovation

摘　　要：通过对伊犁盆地层间氧化带砂岩型铀矿床稀土元素地球化学行为特征的分析和蚀源区岩石对比,初步认为该区稀土元素主要来自蚀源区的安山岩和花岗岩,与玄武岩无关;对ΣREE的研究表明,在层间氧化岩石带中ΣREE有所亏损;通过对REE的分异性的研究,认为在不同的分带中REE的分异程度不同,在矿石带中分异程度最大,更加富集LREE,并且随着岩石粒径的增大,LREE和HREE的分异也有增大的趋势;通过对巴什布拉克砂岩型铀矿床稀土元素地球化学特征分析表明,矿石ΣREE明显低于围岩的ΣREE,矿石和围岩ΣREE差别较大,这可能是由于该矿床在成岩成矿和搬运过程中有大量的REE被淋滤流失掉的缘故,但围岩的REE分布模式和矿石的REE分布模式基本一致,这也反映了该区成岩成矿的继承性特征。通过对伊犁盆地流体和岩石的pH值分布情况研究表明,层间氧化岩石带和原生还原岩石带的pH值相似,而矿石带的pH值偏低,这与在偏碱性条件下,REE和U的络合物容易形成,并且REE和U的络合物随着pH值的降低而迁移和沉淀富集是相吻合的。By analyzing the geochemical behavior characteristics of rare earth elements in the interlayer oxidation zone sandstone type uranium deposit in the Ili Basin and comparing the rocks in the source area,it is preliminarily believed that the rare earth elements in this area mainly come from andesite and granite in the source area,and are not related to basalt;rightΣREE's research indicates that in the interlayer oxidized rock zoneΣREE has incurred losses;Through the study of the differentiation of REE,it is believed that the degree of differentiation of REE varies in different zones,with the highest degree of differentiation in the ore zone,which is more enriched in LREE.Moreover,as the rock particle size increases,the differentiation of LREE and HREE also tends to increase;Analysis of the geochemical characteristics of rare earth elements in the Bashbulak sandstone type uranium deposit indicates that the oreΣREE is significantly lower than the surrounding rockΣREE,ore and surrounding rockΣthere are significant differences in REE,which may be due to a large amount of REE being lost by leaching during the process of diagenesis,mineralization,and transportation of the deposit.However,the REE distribution pattern of the surrounding rock is basically consistent with that of the ore,which also reflects the inheritance characteristics of diagenesis and mineralization in the area.Through the study of the pH distribution of fluids and rocks in the Ili Basin,it is shown that the pH values of interlayer oxidized rock zones and primary reduced rock zones are similar,while the pH values of ore zones are low.This is consistent with the fact that under slightly alkaline conditions,REE and U complexes are easily formed,and REE and U complexes migrate and precipitate and enrich with the decrease of pH value.

关 键 词：伊犁盆地层间氧化带砂岩型铀矿床 巴什布拉克砂岩型铀矿床 稀土元素 地球化学 铀 

分 类 号：P619.14[天文地球—矿床学] P595[天文地球—地质学]