吐哈盆地十红滩铀矿床稀土元素地球化学特征浅析

摘要

通过对吐鲁番-哈密盆地十红滩层间氧化带犁铀矿床容矿层样品采集和稀土元素测试、研究,分析认为该矿床容矿层的原岩类型主要为花岗岩,主要来自于南部蚀源区觉罗塔格山,其形成于被动大陆边缘,为低温成岩成矿作用的产物,进一步证明该砂岩型铀矿床形成于低温条件下.不同地球化学环境稀土元素含量变化趋势显示,在层间氧化作用过程中发生了稀土元素的富集和分馏作用,氧化作用越强,越富集轻稀土元素,稀士元素分馏作用越强,喻示着水解作用愈强,铀的氧化迁移作用愈剧烈.在氧化还原过渡带,伴随着铀矿化的形成则发生了重稀土元素的富集作用,铀与重稀土元素表现出相近的地球化学性质,二者沉淀均与碳酸盐络合物的离解有关.%By sampling in the ore-hosting bed rock of the Shihongtan interlayer oxidized zone type uranium deposit, detection and studying on the REE, writers considered that the type of initial rock in the ore-hosting bed is granite, formed at passive continental margin, which comes mostly from Jueluotage Mountain of southern denudation zone. The rock is product of low temperature lithogenesis, and it is proved that the deposit forms on lower temperature. With different geochemical REE on the content variation indicates that there is REE concentration and fractionating in the process of interlayer oxidized effect,the stronger oxidized effect result in more light REE and the stronger REE fractionating effect,means the stronger hydrolytic action and uranium oxidized and moving action. With the forming of uranium mineralization in the redox transitional zone on, heavy REE concentration occurs. Uranium and heavy REE manifest the similar geochemical characteristic. Their deposition are related to the dissociationof complexion of carbonation.