准噶尔盆地东缘老君庙地区砂岩型铀矿成矿要素遥感识别

Remote Sensing Identification of Metallogenic Factors of Sandstone-Type Uranium Deposit in the Laojunmiao Area, Eastern Junggar Basin

盆地边缘砂岩型铀矿的成矿要素包括构造斜坡带、充足的铀源、携铀地下水的补-径-排体系以及氧化-还原过渡带等。遥感技术的发展为快速识别以上成矿要素,及高效勘查砂岩型铀矿提供了机会。本文以准噶尔盆地东缘老君庙地区为研究对象,利用GF-5高光谱分辨率影像进行蚀变矿物提取、Sentinel-2影像及DEM数据建立三维地形,结合航磁航放数据对该区砂岩型铀矿成矿条件进行遥感识别。结果表明,研究区处于盆缘缓倾的构造斜坡带,并具有较好的地下水补-径-排体系;地表蚀变矿物主要为高岭石、少量伊利石,并呈带状分布;航磁异常的弱变化表明研究区处于氧化-还原过渡带。综合遥感、航磁航放资料与铀异常信息,识别出研究区砂岩型铀矿形成相关的铀源、补-径-排体系和蚀变矿物等成矿要素,对盆地周缘找矿具有参考意义。

The genesis of sandstone-type uranium deposits in basin margins encompasses various factors,including tectonic slope zone,ample uranium sources,replenishment mechanisms,uranium-carrying groundwater drainage system,and oxidation-reduction transition zone.Advances in remote sensing technology have presented a valuable opportunity for the fast identification of these metallogenic elements,and have promoted the efficient exploration of sandstone-type uranium deposits.Taking the Laojunmiao area in the eastern margin of Junggar Basin as an example,this work extracted altered minerals based on GF-5 hyperspectral resolution images,Sentinel-2 images and DEM data to establish three-dimensional terrain.Integrated with aeromagnetic and aerial radioactivity data,the remote sensing identification of metallogenic conditions was conducted for sandstone type uranium ores.The results show that the study area is located in the slope zone of gentle dip along the basin margin,and has a good groundwater replenishment and drainage system.The surface alteration minerals are mainly kaolinite and a small amount of illite,with a banded distribution.The weak variation of aeromagnetic anomalies indicates that the study area is in an oxidation-reduction transition zone.Integrated remote sensing,aeromagnetic,aerial radioactivity and uranium anomaly information has identified the metallogenic elements related to the formation of sandstone type uranium deposits,such as uranium source,supplement-diameter drainage system and altered minerals,which will provide reference significance for prospecting around the basin.