砂岩型铀矿航磁微弱异常提取方法

在中—新生代盆地区,受盆地盖层影响,砂岩型铀矿的航磁ΔT异常信息不明显,这直接影响利用航磁资料寻找砂岩型铀矿的应用效果。开展盆地内航磁微弱信息提取方法的研究,能充分发挥航磁资料在砂岩型铀矿勘查中的作用。本文总结了砂岩型铀矿形成微弱航磁异常的机理,分析界定了航磁微弱磁异常的定量范围,以1∶5万高精度航磁数据为基础,通过对内蒙古西部已发现的层间氧化带砂岩型铀矿床航磁特征进行分析研究,总结出一套利用高通滤波提取砂岩型铀矿上方航磁微弱信息的方法,使用该方法在内蒙古二连盆地某铀成矿带开展了航磁微弱异常提取实验,在3个已发现的氧化带砂岩型铀矿上方提取出航磁微弱异常信息,为利用高精度航磁测量方法在中—新生代盆地区寻找砂岩型铀矿探索出一条新途径。

A study of the method of extracting aeromagnetic weak anomalies from sandstone-type uranium deposits

In the Mesozoic and Cenozoic basin areas,the aeromagneticΔT anomaly information of sandstone-type uranium deposits is not obvious due to the influence of the basin cover layer,which directly affects the application effect of using aeromagnetic data to find sandstone-type uranium deposits.The research on the method of extracting weak information of aeromagnetic data in the basin can give full play to the role of aeromagnetic data in the exploration of sandstone-type uranium deposits.This paper summarizes the mechanism of the formation of weak aeromagnetic anomalies in sandstone-type uranium deposits,and analyzes and defines the quantitative range of weak aeromagnetic anomalies.On the basis of the 1∶50,000 high-precision aeromagnetic data and through the analysis and research on the aeromagnetic characteristics of the sandstone-type uranium deposits discovered in western Inner Mongolia,a high-pass filtering method was used to extract the aeromagnetic data above the sandstone-type uranium deposit.This method was used to carry out aeromagnetic weak anomaly extraction experiments in a uranium metallogenic belt in Erlian Basin of Inner Mongolia.The aeromagnetic weak anomaly information was extracted above three discovered interlayer oxidation zones of sandstone-type uranium deposits,thus finding a new way in the search for sandstone-type uranium deposits in the Meso-Cenozoic basin area.