航磁梯度数据解释新方法在迁安铁矿勘探中的应用

New interpretation methods of aeromagnetic gradient data in application of iron mine exploration of Qianan area

为更加清晰和准确地利用磁梯度数据获得地质体的分布特征,笔者采用解析信号总水平导数法和梯度欧拉反褶积技术组合实现磁梯度数据的解释,解析信号总水平导数的极值可有效地圈定出矿体的分布范围,梯度欧拉反褶积法可有效地避免背景异常的干扰,从而准确地给出磁性体的位置和深度信息。理论模型证明解析信号水平导数法和梯度欧拉反褶积法的组合可准确地获得磁性体的水平范围和深度。应用于河北迁安地区磁梯度数据的解释,圈定出5个呈条带状分布的较大型铁矿藏,埋深在200~450 m。

In order to obtain the distribution feature of geological bodies by the magnetic gradient data clearly and correctly,the authors use total horizontal derivative of analytic signal and gradient Euler deconvolution methods to interpret aeromagnetic gradient data. The maximum of the total horizontal derivative of analytic signal method can define the distribution of the ore bodies,and gradient Euler deconvolution can avoid the interference of background anomaly,and obtain the location and depth of the magnetic source correctly. Theoretical tests show that the combination of total horizontal derivative method and gradient Euler deconvolution method can obtain horizontal range and depth of the magnetic source correctly. The authors apply the presented methods to interpret magnetic gradient data in Qian＇an area of Hebei,and delineate five larger iron ore resources in banded distribution,with burial depths of200 m to 450 m.