鄂尔多斯盆地南缘重磁场特征及其与砂岩型铀矿关系

鄂尔多斯盆地南部是我国重要的砂岩型铀矿产地之一。为了研究该区重磁场特征与砂岩型铀矿展布规律的关系,预测砂岩型铀矿有利区,本文在对鄂尔多斯盆地南缘重、磁资料处理与解释的基础上,推断了研究区的断裂构造,探讨了断裂构造、重磁场平面特征与已知铀矿点的关系,预测了铀矿成矿有利区。研究结果表明:研究区发育的断裂走向有NE向、近EW向、近SN向和NW向4组;已知铀矿(床)点多分布于断裂与次级断裂交汇处,重力梯级带、局部重力高边缘和磁力中低缓异常区。研究区有平凉、宜君-黄陵、彬县-旬邑3个铀矿有利成矿区。

The relationship between features of gravity and magnetic field and sandstone-type uranium deposits in the south of Ordos basin

The southern Ordos basin is one of the important producing areas of sandstone uranium deposits. This work aims to reveal the relationship between the characteristics of the gravity and magnetic field and uranium deposits and infer the favorable areas of sandstone-type uranium deposits in the south of the Ordos basin. Based on the gravity and magnetic data processing and interpretation, we discussed the fault structures and the relationship of planar distribution features of gravity and magnetic field with the discovered uranium spots, and predicted the favorable areas of uranium deposits. The results show that the main faults in this area can be divided into four groups: NE-trending faults, nearly EW-trending faults, nearly SN-trending and NW-trending faults. The discovered uranium ore spots are generally distributed in the intersection of faults and secondary faults, gravitational gradient zone, residual gravity anomaly highs and the middle-low aeromagnetic anomaly areas. Three predicted favorable areas for uranium deposits are Pingliang, Yijun-Huangling and Bingxian-Xunyi.