河南内黄—浚县一带重磁异常与深部磁铁矿靶区预测研究

The research on the prediction of gravity and magnetic anomalies and deep magnetite target areas in the Neihuang-Xunxian area of Henan Province

河南内黄—浚县一带位于太古宙基底隆起区,且分布有较好的重、磁异常,具备寻找沉积变质型磁铁矿床的有利条件。然而20世纪70年代以来,受制于浅部找矿认识的局限性,一直未能取得找矿突破。笔者以深部磁铁矿找矿靶区为目标,通过中心识别技术(解析信号振幅ASM)、边缘识别技术(NVDR?THDR)获得了研究区隐伏磁性体的平面位置(中心及边界),利用欧拉反褶积获得了研究区隐伏磁性体的埋深信息,利用相关系数分析了该区重磁异常的同源性特征;结合已知钻孔对研究区重点磁异常进行了2.5D拟合反演,确定了隐伏磁性体的规模及空间展布特征,研究结果表明主要磁异常对应的隐伏磁性体埋深在500~1200 m,且深部含矿性均好于浅部,深部找矿潜力较大。综合地质矿产条件,预测了瓦岗—榆涧、南张保等2个磁铁矿深部找矿靶区,建议作为后续开展深部找矿的重点方向,以尽快实现该区的深部找矿突破。

The Neihuang?Xunxian area in Henan Province is located in the Archaean basement uplift area,and has good gravity and magnetic anomalies.It has favorable conditions in the search for sedimentary metamorphic magnetite deposits.However,since the 1970s,due to the limitations of shallow prospecting knowledge,no breakthrough has been made in prospecting.Aimed at the target area of deep magnetite prospecting,the authors detected the plane position(center and boundary)of the concealed magnets in the study ar?ea by central recognition technology(analytical signal amplitude ASM)and edge recognition technology(NVDR?THDR),obtained the burial information of the concealed magnets in the study area by Euler deconvolution,and analyzed the homologous characteristics of gravity and magnetic anomalies in the study area by correlation coefficient.Combined with known boreholes,2.5D fitting inversion of key magnetic anomalies in the study area was carried out,and the scale and spatial distribution characteristics of the concealed magnets were determined.The results show that the buried depth of the concealed magnets corresponding to the main magnetic anomalies is 500~1200 m,and the ore?bearing property in the deep part is better than that in the shallow part,so the prospecting potential in the deep part is great.On the basis of comprehensive geological and mineral conditions,two deep prospecting target areas of Wagang?Yujian and Nanzhangbao magnetite ores were delineated.It is suggested that they should be the key directions in further deep prospecting with the purpose of achieving a breakthrough in deep prospecting in this area as soon as possible.