高精度航磁测量在陕西省山阳县小河镇找矿中的应用

Application of High Precision Aeromagnetic Prospecting in Xiaohe Township,Shanyang County,Shaanxi Province

自20世纪60年代,陕西省山阳县小河镇一带先后发现了多处金属矿点。近60a的开采,该区部分铜矿已处于采毕关停状态,除袁家沟铜矿深部近期获得重要发现外,其它金属矿尚未取得关键性突破。据以往地质资料显示该区成矿条件良好,其深部与已知矿体外围仍具较大找矿潜力,为此中煤航测遥感局对小河镇研究区开展了高精度航磁测量,获得了较好的高精度航磁异常特征。主要地质体与航磁异常对比表明,地表已知侵入岩体和矽卡岩(矿体)在空间位置上均位于局部高磁异常点附近,以往地质资料和本次研究实际测量结果证实,因矽卡岩(矿体)围绕侵入岩体产出,侵入岩体和矽卡岩(矿体)可视为综合磁性体,其高航磁异常,可确定由综合磁性体含有的金属矿引起;而地表未见侵入体和矽卡岩(矿体)的局部高磁异常附近也有可能存在地下隐伏岩体和矿体,可大致圈定为下一步找矿的靶区。

Since the 1960s,many metal ore spots have been found in the Xiaohe Township surroundings,Shanyang County,Shaanxi Province.About 60 years’exploitation,parts of copper deposit are in the status of completed and shut-down.Besides some recent important findings in deep part of the Yuanjiagou copper mine,other metal ore deposits have no critical breakthrough yet.Previous geological data have shown that the metallogenetic conditions in the area are quite good,thus the deep part and peripheral of known ore deposits still have better prospecting potential.For this reason,the Aerial Photogrammetry and Remote Sensing Bureau,CNACG has carried out high precision aeromagnetic prospecting for the Xiaohe Township study area and grasped high precision aeromagnetic anomaly features.The comparison of main geologic body and aeromagnetic anomaly has shown that the spatial positions of known intrusive and skarn(orebody)are all near local high magnetic anomaly,the previous geological data and this study measured results have verified that because of skarn(orebody)occurrence around intrusive,thus the intrusive and skarn(orebody)can be considered as an integrated magnetic body,its high aeromagnetic anomaly should be caused by metal ore in the integrated magnetic body.Near the local high magnetic anomaly but without surface intrusive and skarn(orebody)can be seen,possibly existed underground concealed intrusive and orebody,thus can be delineated as next prospecting target area.