微航磁异常与可地浸砂岩型铀矿床

可地浸砂岩型铀矿床由于其上覆盖层较厚,地表异常信息十分微弱,找矿难度相当大。本文通过研究新疆伊犁盆地510、511、512等3个已知可地浸砂岩型铀矿床的航磁资料,发现这些矿床上方均存在微航磁异常,根据可地浸砂岩型铀矿的成矿地球化学机制,对微航磁异常的形成机理作了进一步探讨,结合试验区的实际预测成果,指出与氧化还原过渡带有关的可地浸砂岩型铀矿床上方存在微航磁异常,高精度航磁完全能探测到。微航磁异常是此类矿床的特征异常之一,可以作为一种重要标志信息运用于前期成矿预测。

Weak-aeromagnetic anomaly and in-situ leachable sandstone-type uranium deposit

Anomaly over in-situ leachable sandstone type uranium deposit appears rather weak due to the thick cover, therefore, prospecting in this area is extremely difficult. After careful study of aeromagnetic data of three known deposits No. 510, 511 and 512 in the southern rim of Yili basin, this paper discovers that there are weak-aeromagnetic anomalies over these deposits, and makes further discussion on the forming mechanism of weak-aeromagnetic anomaly according to the metallogenetic geochemical mechanism of this type uranium deposit. Combining the practical prediction, the paper concludes that there are weak-magnetic anomalies over in-situ leachable sandstone type uranium deposits related to redox transitional zone and high precision aeromagnetic survey can detect these anomalies, so weak-aeromagnetic anomaly can be regarded as one of characteristic anomalies for this type deposit and can act as a kind of direct guiding information in the pre-phase metallogenetic prediction.