银额盆地赛尔亥那地区铀矿化特征及成因研究
Study on the Characteristics and Genesis of Uranium Mineralization in Saierhaina Area in Yin'e Basin
李伟涛 1刘武生 1纪宏伟 1李子颖 1牛霆 2罗森森 2杨喆1
作者信息
- 1. 核工业北京地质研究院 中核集团铀资源勘查与评价技术重点实验室,北京 100029
- 2. 核工业二〇三研究所,陕西 西安 710086
- 折叠
摘要
银额盆地赛尔亥那地区发现的地表铀矿化带,前期认为是层间氧化铀成矿作用形成的砂岩型铀矿化,本次研究发现,赋矿岩石类型为含铀白云质磷质岩及含铀磷质粉砂岩.矿石中赋存大量的微晶磷灰石,呈微晶(粒径＜1 μm)集合体形式.全岩主微量分析显示U与P2O5、CaO呈较好的正相关,磷灰石微区原位(LA-ICP-MS)主微量分析结果显示U与P2O5、CaO、∑REE等均呈较好的正相关,高倍扫描电镜下未发现铀矿物,认为铀是以类质同象形式赋存在磷灰石中.铀矿石岩性岩相特征、磷灰石微区原位微量元素组合特征及共伴生矿物成因等表明,富铀磷灰石是在沉积成岩过程中,微生物参与作用下形成的.因此,赛尔亥那地区铀矿找矿思路应兼顾潜水-层间氧化型及沉积成岩型.
Abstract
The early surface uranium mineralization zone discovered in the Saierhaina area of Yin'e Basin was initially believed to be sandstone-type formed by groundwater or interlayer oxidation.This study revealed the ore host rocks are dolomitic phosphatic rock and phosphatic siltstone.The ores contain a large amount of microcrystalline apatite(francolite)which was identified as carbon-fluorine apatite by electron probe and laser ablation techniques and occured as microcrystalline aggregates(＜1μm)in form.Whole-rock major and trace element analysis showed a good positive correlation between uranium content and P,Ca content,while the in-situ analysis(LA-ICP-MS)of apatite indicated a positive correlation between uranium content and P,Ca,REE,and other elements.No uranium minerals were found through high-resolution scanning electron microscope,indicatting that uranium is incorporated into apatite in the form of solid solution.Lithology and lithofacies,in-situ trace element composition and rare earth element characteristics of apatite and genesis of associated minerals showed that the uranium-rich apatite was formed during the diagenesis process under the influence of microbial activity.Therefore,the uranium exploration in Saierhaina area should pay attention to the mineralization of both phreatic-interlayer oxidation and sedimentary diagenesis.
关键词
银额盆地/赛尔亥那/含铀磷质岩/磷灰石Key words
Yin'e Basin/Saierhaina/uranium-bearing phosphatic rock/apatite引用本文复制引用
基金项目
中核集团集中研发项目(中核科发2021-143号)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据