摘要
海力锦铀矿床控矿灰色砂岩垂向上具有“两红夹一灰”特征,铀矿体呈多层板状,与传统的层间氧化带砂岩型铀矿明显不同。文章通过对赋矿灰色砂岩中黄铁矿微区微量元素和硫同位素特征研究,反演海力锦铀矿床成矿流体性质及来源,主要获得了以下几点认识:(1)海力锦铀矿床含矿层黄铁矿赋存形式包括胶状、草莓状,铀矿物常与草莓状或胶状黄铁矿共伴生于有机质胞腔内或矿物粒间孔隙。(2)黄铁矿微量元素特征显示,As、Mo、Sb等亲硫性元素从核部到边部含量增高,Mo、Ni、Zn、Cu、Ba等元素与U具有较好的正相关性,这些元素在大气降水中难以沉淀和富集,往往富集于深部还原性流体中。硫同位素δ34SV-CDT值显示从核部到边部明显降低的特征,表明黄铁矿形成环境发生了较大改变,指示海力锦铀矿床成矿流体可能为深部具有一定温度的还原性流体。(3)松辽盆地西南部深部发育厚度大且面积广的富铀烃源岩,海力锦铀矿床东南部F1断裂为沟通深部富铀烃源岩和含矿层的深大断裂,据此认为海力锦铀矿床成矿流体可能来自深部还原性流体(富铀烃源岩),控矿灰色砂岩为还原性流体对原生氧化沉积建造的还原改造。
The ore-controlling gray sandstones of Hailijin uranium deposit are surrounded by oxidized sandstones on vertical,the ore body are in multi-stratiform and tabular shape,which is quite different from the traditional sandstone type uranium deposit of interlayer oxidation.In this paper,the characteristics of trace elements and sulfur isotopes of pyrite in the ore-bearing gray sandstones were collected to study the properties and sources of ore-forming fluid in Hailijin uranium deposit,the following understandings were obtained:(1)Pyrite in ore-bearing layer of Hailijin uranium deposit mainly occurs in colloidal,framboid and granular forms,and the uranium minerals are often associated with colloidal or framboid pyrite in the organic cell cavity or intergranular pores of minerals.(2)The characteristics of trace elements in pyrite show that the content of sulfurophilic elements such as As,Mo and Sb increases from the core to the edge,and Mo,Ni,Zn,Cu and Ba show a better positive correlation with U.These elements are generally difficult to precipitate and enrich in atmospheric precipitation,comparatively,they’re enriched in deep reducing fluids generally.Theδ34SV-CDT value of sulfur isotope shows a significant decrease from the core to the edge,indicating that the pyrite formation environment has changed greatly.It is suggested that the ore-forming fluid of Hailijin uranium deposit may derives from deep reducing fluid with a certain temperature.(3)The uranium-rich hydrocarbon source rocks with large thickness and wide area are occurred in the southwest Songliao Basin,and the F1 fault in the southeast of Hailijin uranium deposit connected the deep uranium-rich hydrocarbon source rocks and ore-bearing layers.Therefore,it was believed that the ore-forming fluid of Hailijin uranium deposit may originated from the deep reducing fluid(uraniumrich hydrocarbon source rocks),and the ore-controlling gray sandstone was the reduction transformation of the primary oxidized sedimentary formation by the reducing fluid.
作者
田明明
李子颖
张云龙
贾立城
邱林飞
邢作昌
宁君
李继木
唐国龙
林效宾
TIAN Mingming;LI Ziying;ZHANG Yunlong;JIA Licheng;QIU Linfei;XING Zuochang;NING Jun;LI Jimu;TANG Guolong;LIN Xiaobin(Beijing Research Institute of Uranium Geology,Beijing 100029,China;Geologic Party No.243,CNNC,Chifeng,Inner Mongolia 024000,China)
出处
《铀矿地质》
CSCD
2024年第1期119-128,共10页
Uranium Geology
基金
中核集团集中研发项目(编号:中核科发2021-143号)
国家重点基金项目(编号:U2167210)联合资助
关键词
黄铁矿
原位硫同位素
成矿流体
海力锦铀矿床
松辽盆地
pyrite
in-suit sulfur isotope
ore-bearing fluid
Hailijin uranium deposit
Songliao Basin
